Trial Outcomes & Findings for Communicating Multiple Disease Risks: A Translation of Risk Prediction Science (NCT NCT03255291)

NCT ID: NCT03255291

Last Updated: 2020-01-18

Results Overview

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 554 participants
• Primary outcome timeframe: Baseline and up to 90 days
• Results posted on: 2020-01-18

Participant Flow

Participant milestones

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Overall Study STARTED	93	90	91	90	95	95
Overall Study COMPLETED	80	78	85	84	88	85
Overall Study NOT COMPLETED	13	12	6	6	7	10

Reasons for withdrawal

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Overall Study Determined to be ineligible	10	12	6	6	5	10
Overall Study Baseline data collection issues	3	0	0	0	2	0

Baseline Characteristics

Communicating Multiple Disease Risks: A Translation of Risk Prediction Science

Baseline characteristics by cohort

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=80 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep n=78 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise n=85 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Sleep n=84 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise n=88 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep n=85 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Total n=500 Participants Total of all reporting groups
Age, Continuous	47.2 years STANDARD_DEVIATION 9.8 • n=5 Participants	47.3 years STANDARD_DEVIATION 8.7 • n=7 Participants	50.3 years STANDARD_DEVIATION 9.9 • n=5 Participants	49.8 years STANDARD_DEVIATION 9.9 • n=4 Participants	46.8 years STANDARD_DEVIATION 10.7 • n=21 Participants	47.2 years STANDARD_DEVIATION 10.5 • n=10 Participants	48.1 years STANDARD_DEVIATION 10.0 • n=115 Participants
Sex: Female, Male Female	63 Participants n=5 Participants	67 Participants n=7 Participants	68 Participants n=5 Participants	67 Participants n=4 Participants	69 Participants n=21 Participants	73 Participants n=10 Participants	407 Participants n=115 Participants
Sex: Female, Male Male	17 Participants n=5 Participants	11 Participants n=7 Participants	17 Participants n=5 Participants	17 Participants n=4 Participants	19 Participants n=21 Participants	12 Participants n=10 Participants	93 Participants n=115 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	4 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants	5 Participants n=4 Participants	4 Participants n=21 Participants	2 Participants n=10 Participants	17 Participants n=115 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	76 Participants n=5 Participants	77 Participants n=7 Participants	84 Participants n=5 Participants	79 Participants n=4 Participants	84 Participants n=21 Participants	83 Participants n=10 Participants	483 Participants n=115 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	0 Participants n=115 Participants
Race/Ethnicity, Customized American Indian/Alaskan Native	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=10 Participants	2 Participants n=115 Participants
Race/Ethnicity, Customized Asian/Pacific Islander	1 Participants n=5 Participants	0 Participants n=7 Participants	2 Participants n=5 Participants	0 Participants n=4 Participants	1 Participants n=21 Participants	2 Participants n=10 Participants	6 Participants n=115 Participants
Race/Ethnicity, Customized Black/African American	27 Participants n=5 Participants	35 Participants n=7 Participants	26 Participants n=5 Participants	37 Participants n=4 Participants	37 Participants n=21 Participants	23 Participants n=10 Participants	185 Participants n=115 Participants
Race/Ethnicity, Customized White/Caucasian	49 Participants n=5 Participants	43 Participants n=7 Participants	50 Participants n=5 Participants	40 Participants n=4 Participants	46 Participants n=21 Participants	56 Participants n=10 Participants	284 Participants n=115 Participants
Race/Ethnicity, Customized Multiracial/Other	2 Participants n=5 Participants	0 Participants n=7 Participants	6 Participants n=5 Participants	7 Participants n=4 Participants	4 Participants n=21 Participants	4 Participants n=10 Participants	23 Participants n=115 Participants
Region of Enrollment United States	80 participants n=5 Participants	78 participants n=7 Participants	85 participants n=5 Participants	84 participants n=4 Participants	88 participants n=21 Participants	85 participants n=10 Participants	500 participants n=115 Participants
Vocational-technical training or less	20 Participants n=5 Participants	20 Participants n=7 Participants	14 Participants n=5 Participants	14 Participants n=4 Participants	15 Participants n=21 Participants	14 Participants n=10 Participants	97 Participants n=115 Participants
Body mass index (BMI) - Obese	38 Participants n=5 Participants	32 Participants n=7 Participants	46 Participants n=5 Participants	52 Participants n=4 Participants	48 Participants n=21 Participants	42 Participants n=10 Participants	258 Participants n=115 Participants
Body mass index (BMI) - Overweight	21 Participants n=5 Participants	23 Participants n=7 Participants	19 Participants n=5 Participants	15 Participants n=4 Participants	24 Participants n=21 Participants	25 Participants n=10 Participants	127 Participants n=115 Participants
1+ comorbidity	14 Participants n=5 Participants	6 Participants n=7 Participants	21 Participants n=5 Participants	17 Participants n=4 Participants	19 Participants n=21 Participants	15 Participants n=10 Participants	92 Participants n=115 Participants
Baseline Exercise (minutes per week in last 7 days)	56.7 minutes STANDARD_DEVIATION 44.8 • n=5 Participants	56.9 minutes STANDARD_DEVIATION 45.1 • n=7 Participants	53.9 minutes STANDARD_DEVIATION 47.4 • n=5 Participants	50.2 minutes STANDARD_DEVIATION 45.4 • n=4 Participants	41.3 minutes STANDARD_DEVIATION 41.1 • n=21 Participants	56.0 minutes STANDARD_DEVIATION 43.4 • n=10 Participants	52.3 minutes STANDARD_DEVIATION 44.7 • n=115 Participants
Self-Reported Health	3.0 units on a scale STANDARD_DEVIATION 1.0 • n=5 Participants	3.1 units on a scale STANDARD_DEVIATION 0.9 • n=7 Participants	3.0 units on a scale STANDARD_DEVIATION 1.0 • n=5 Participants	3.1 units on a scale STANDARD_DEVIATION 0.9 • n=4 Participants	3.0 units on a scale STANDARD_DEVIATION 0.9 • n=21 Participants	3.0 units on a scale STANDARD_DEVIATION 0.9 • n=10 Participants	3.0 units on a scale STANDARD_DEVIATION 0.9 • n=115 Participants
Numeracy	1.6 units on a scale STANDARD_DEVIATION 1.0 • n=5 Participants	1.3 units on a scale STANDARD_DEVIATION 0.9 • n=7 Participants	1.7 units on a scale STANDARD_DEVIATION 1.0 • n=5 Participants	1.5 units on a scale STANDARD_DEVIATION 1.1 • n=4 Participants	1.5 units on a scale STANDARD_DEVIATION 1.1 • n=21 Participants	1.6 units on a scale STANDARD_DEVIATION 1.0 • n=10 Participants	1.5 units on a scale STANDARD_DEVIATION 1.0 • n=115 Participants
Graph literacy	2.5 units on a scale STANDARD_DEVIATION 1.1 • n=5 Participants	2.1 units on a scale STANDARD_DEVIATION 1.2 • n=7 Participants	2.2 units on a scale STANDARD_DEVIATION 1.2 • n=5 Participants	2.3 units on a scale STANDARD_DEVIATION 1.1 • n=4 Participants	2.2 units on a scale STANDARD_DEVIATION 1.2 • n=21 Participants	2.6 units on a scale STANDARD_DEVIATION 1.0 • n=10 Participants	2.3 units on a scale STANDARD_DEVIATION 1.1 • n=115 Participants

PRIMARY outcome

Timeframe: Baseline and up to 90 days

Population: Additional participants who did not complete the 90 day follow up survey or completed the survey over 8 weeks late, were inattentive responders, had text messaging errors, or were considered an outlier (\>99th percentile) in change in minutes of exercise per week were excluded for analysis

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=70 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep n=66 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise n=72 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep n=67 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise n=73 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep n=72 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Change From Baseline to 90-day Follow-up in Self Reported Weekly Minutes of Exercise	92.2 minutes Standard Error 12.7	37.5 minutes Standard Error 13.4	63.1 minutes Standard Error 12.4	60.0 minutes Standard Error 12.9	50.1 minutes Standard Error 12.5	49.3 minutes Standard Error 13.0

PRIMARY outcome

Timeframe: Baseline

Population: This study was designed as a 3X2 factorial design \& only the risk display format intervention (risk ladder, table, or text) was looked at for this outcome, as participants had not yet received the mental imagery intervention, thus it could not affect this outcome.

• Risk display format = risk ladder, table, or text
• Gist comprehension of risk information: being able to extract the bottom-line meaning of information provided by the website (e.g., if exercising decreased heath risk)
• Measured by the sum of (4) questions coded as correctly comprehending risk information (1 point) or incorrectly comprehending risk information (0 points), with a total score range of 0=low comprehension to 4=high comprehension. Higher comprehension is considered a better outcome.
• All comprehension questions have an additional "don't know" option, which is counted as incorrect.
• To limit participant burden, the investigators assessed comprehension for diabetes only, instead of all diseases as planned.
• Comprehension will not be assessed for people who report a history of diabetes because they are not given risk information.

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=125 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep n=120 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise n=127 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Difference in Gist Comprehension of Risk Information by Risk Display Format	3.6 score on a scale Standard Error 0.1	3.4 score on a scale Standard Error 0.1	3.2 score on a scale Standard Error 0.1	—	—	—

PRIMARY outcome

Timeframe: Baseline

Population: This study was designed as a 3X2 factorial design \& only the risk display format intervention (risk ladder, table, or text) was looked at for this outcome, as participants had not yet received the mental imagery intervention, thus it could not affect this outcome.

• Risk communication strategy = risk ladder, table, or text
• Verbatim comprehension of risk information: being able to recall the exact information specific to diabetes risk and hours of recommended weekly physical activity
• Measured by the sum of (3) questions coded as correctly comprehending information (1 point) or incorrectly comprehending information (0 points), with a total score range of 0=low comprehension to 3=high comprehension. Higher comprehension is considered a better outcome.
• All comprehension questions have an additional "don't know" option, which is counted as incorrect.
• To limit participant burden, the investigators assessed comprehension for diabetes only, instead of all diseases as planned.
• Comprehension will not be assessed for people who report a history of diabetes because they are not given risk information.

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=125 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep n=120 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise n=127 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Difference in Verbatim Comprehension of Risk Information by Risk Communication Strategy	1.6 score on a scale Standard Error 0.1	1.6 score on a scale Standard Error 0.1	1.5 score on a scale Standard Error 0.1	—	—	—

PRIMARY outcome

Timeframe: Baseline

Population: This study was designed as a 3X2 factorial design \& only the risk display format intervention (risk ladder, table, or text) was looked at for this outcome, as participants had not yet received the mental imagery intervention, thus it could not affect this outcome.

• Risk display format = risk ladder, table, or text
• Self-reported physical activity intentions is defined as intentions to engage in physical activity in the next 3 months
• Measured as an average of three variables, each measured on a 5 point Likert Scale (range: 1=lower intentions to 5=higher intentions)
• Higher intentions are considered a better outcome

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=125 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep n=120 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise n=127 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Difference in Self-reported Intentions to Engage in Physical Activity by Risk Display Format	3.9 score on a scale Standard Error 0.1	4.0 score on a scale Standard Error 0.1	3.8 score on a scale Standard Error 0.1	—	—	—

SECONDARY outcome

Timeframe: 90 days

Population: Due to the limitations of data collection \& concerns about overburdening participants with too many survey questions, the investigators only assessed exercise-related maintenance self-efficacy among participants who engaged in the exercise-related mental imagery condition.

• Maintenance Self-efficacy is defined as being sure one can engage in physical activity even when it is hard
• Measured on a 4 point Likert Scale (range: 1=lower Maintenance Self-efficacy to 4=higher Maintenance Self-efficacy)
• Higher maintenance self-efficacy is considered a better outcome
• Note: to limit participant burden, the investigators used a single item instead of averaging across multiple items

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=229 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Effect of the Intervention on Physical Activity Levels as Measured by Maintenance Self-efficacy	2.95 score on a scale Standard Error 0.05	—	—	—	—	—

SECONDARY outcome

Timeframe: 90 days

Population: Due to the limitations of data collection \& concerns about overburdening participants with too many survey questions, the investigators only assessed exercise-related recovery self-efficacy among participants who engaged in the exercise-related mental imagery condition.

• Recovery Self-efficacy is defined as being sure one can re-engage in physical activity after putting it off
• Measured on a 4 point Likert Scale (range: 1=lower recovery Self-efficacy to 4=higher recovery Self-efficacy)
• Higher recovery self-efficacy is considered a better outcome
• Note: to limit participant burden, the investigators used a single item instead of averaging across multiple items

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=229 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Effect of the Intervention on Physical Activity Levels as Measured by Recovery Self-efficacy	3.26 score on a scale Standard Error 0.05	—	—	—	—	—

SECONDARY outcome

Timeframe: 90 days

Population: Due to the limitations of data collection and concerns about overburdening participants with too many survey questions, the investigators only assessed exercise-related affective attitudes among participants who engaged in the exercise-related mental imagery condition.

• Affective Attitudes to Exercise - Enjoying Behavior is defined as thinking getting regular exercise is enjoyable
• Measured on a 4 point Likert Scale (range: 1=lower Affective Attitudes to Exercise to 4=higher Affective Attitudes to Exercise)
• Higher Affective Attitudes to Exercise - Enjoying Behavior is considered a better outcome
• Note: to limit participant burden, the investigators used a single item instead of averaging across multiple items

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=229 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Effect of the Intervention on Physical Activity Levels as Measured by Affective Attitudes to Exercise - Enjoying Behavior	3.05 score on a scale Standard Error 0.05	—	—	—	—	—

SECONDARY outcome

Timeframe: 90 days

Population: Due to the limitations of data collection and concerns about overburdening participants with too many survey questions, the investigators only assessed exercise-related affective attitudes among participants who engaged in the exercise-related mental imagery condition.

• Affective Attitudes to Exercise - Thinking Behavior is Unpleasant is defined as not thinking getting regular exercise is unpleasant
• Measured on a 4 point Likert Scale (range: 1=lower Affective Attitudes to Exercise to 4=higher Affective Attitudes to Exercise)
• Higher Affective Attitudes to Exercise - Thinking Behavior is Unpleasant is considered a better outcome
• Note: to limit participant burden, the investigators used a single item instead of averaging across multiple items

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=229 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Effect of the Intervention on Physical Activity Levels as Measured by Affective Attitudes to Exercise - Thinking Behavior is Unpleasant	3.19 score on a scale Standard Error 0.05	—	—	—	—	—

SECONDARY outcome

Timeframe: 90 days

Population: Due to the limitations of data collection and concerns about overburdening participants with too many survey questions, the investigators only assessed exercise-related perceived vividness of self-regulatory imagery among participants who engaged in the exercise-related mental imagery condition.

• Perceived Vividness of Self-regulatory Imagery is defined as having clear and vivid images of steps towards getting physical activity
• Measured as an average of two variables measured on a 4 point Likert Scale (range: 1=lower Perceived Vividness of Self-regulatory Imagery to 4=higher Perceived Vividness of Self-regulatory Imagery)
• Higher Perceived Vividness of Self-regulatory Imagery is considered a better outcome
• Note: to limit participant burden, the investigators used a single item instead of averaging across multiple items

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=229 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Effect of the Intervention on Physical Activity Levels as Measured by Perceived Vividness of Self-regulatory Imagery	3.36 score on a scale Standard Error 0.04	—	—	—	—	—

SECONDARY outcome

Timeframe: 90 days

Population: Due to the limitations of data collection and concerns about overburdening participants with too many survey questions, the investigators only assessed exercise-related action planning among participants who engaged in the exercise-related mental imagery condition.

• Action planning is defined as having a detailed plan about getting adequate physical activity
• Measured as an average of three variables measured on a 4 point Likert Scale (range: 1=lower action planning to 4=higher action planning)
• Higher action planning is considered a better outcome
• Note: to limit participant burden, the investigators used a single item instead of averaging across multiple items

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=229 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Effect of the Intervention on Physical Activity Levels as Measured by Action Planning	3.52 score on a scale Standard Error 0.03	—	—	—	—	—

SECONDARY outcome

Timeframe: 90 days

Population: Due to the limitations of data collection and concerns about overburdening participants with too many survey questions, the investigators only assessed exercise-related coping planning among participants who engaged in the exercise-related mental imagery condition.

• Coping planning is defined as having a detailed plan of solving problems that may prevent getting adequate physical activity
• Measured on a 4 point Likert Scale (range: 1=lower Coping Planning to 4=higher Coping Planning)
• Higher coping planning is considered a better outcome
• Note: to limit participant burden, the investigators used a single item instead of averaging across multiple items

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=229 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Effect of the Intervention on Physical Activity Levels as Measured by Coping Planning	2.98 score on a scale Standard Error 0.04	—	—	—	—	—

SECONDARY outcome

Timeframe: 90 days

Population: Due to the limitations of data collection and concerns about overburdening participants with too many survey questions, the investigators only assessed exercise-related action self-efficacy among participants who engaged in the exercise-related mental imagery condition.

• Action self-efficacy is defined as having the confidence to engage in physical activity
• Measured on a 4 point Likert Scale (range: 1=lower Action Self-efficacy to 4=higher Action Self-efficacy)
• Higher Action Self-efficacy is considered a better outcome
• Note: to limit participant burden, the investigators used a single item instead of averaging across multiple items

Outcome measures

Measure	Risk Display Format:Risk Ladder:Imagery Behavior:Exercise n=229 Participants * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Risk Ladder:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Table: Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Exercise * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down an exercise goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.	Risk Display Format:Text:Imagery Behavior:Sleep * With help from a research assistant, participants complete the Risk Assessment App. The App asks demographic \& health questions. It then provides personalized risk estimates for participants' current activity level \& how it would change with regular exercise. * Participants take Baseline Survey 1. * Participants listen to an audio recording that guides them through a mental imagery activity. They write down a sleep goal \& are asked to practice the mental imagery twice a day for 3 weeks. * Participants take Baseline Survey 2. * Participants receive text messages reminding them to practice the mental imagery twice daily for 5 minutes each time (3 texts a week for 3 weeks). * Participants take surveys via text at the end of each week for 4 weeks. * 90 days post-baseline, participants complete a survey sent through the mail. * Participants may be contacted for another survey 1 year later.
Effect of the Intervention on Physical Activity Levels as Measured by Action Self-efficacy	3.36 score on a scale Standard Error 0.04	—	—	—	—	—

Adverse Events

Risk Display Format:Risk Ladder:Imagery Behavior:Exercise

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Risk Display Format:Risk Ladder:Imagery Behavior:Sleep

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Risk Display Format:Table:Imagery Behavior:Exercise

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Risk Display Format:Table:Imagery Behavior:Sleep

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Risk Display Format:Text:Imagery Behavior:Exercise

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Risk Display Format:Text:Imagery Behavior:Sleep

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Erika Waters, MPH, Ph.D.

Washington University School of Medicine

Phone: 314-286-2757

Email: waterse@wustl.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place