Trial Outcomes & Findings for Assessing Mechanisms of Anxiety Reduction in Animal-assisted Interventions (NCT NCT03249116)

Last Updated: 2020-10-08

Results Overview

The state scale of the State-Trait Anxiety Inventory (STAI) was used to measure state-level anxiety. We used the six-item short form of the STAI, which asks participants to rate how each of the six words reflects their feelings (calm, upset, relaxed, worried, tense, content). The short form was originally administered as a four-point scale, which we further modified to a three-point scale for feasibility in administering repeatedly over a short time period (response options for each item followed the format: very calm, calm, not calm). Responses to the six items were used to create a sum score at each time point with a possible range of 3 to 18 (higher scores indicate higher levels of anxiety).

Recruitment status

COMPLETED

Study phase

Target enrollment

75 participants

Primary outcome timeframe

Self-reported anxiety was measured at six time points, during: (Time 1; 0 min) baseline, (Time 2; 30 min) anticipation, (Time 3; 35 min) preparation, (Time 4; 45 min) speech, (Time 5; 60 min) recovery period 1, and (Time 6; 75 min) recovery period 2.

Results posted on

2020-10-08

Participant Flow

Participants were 75 adolescents ages 13-17 on a continuum of social anxiety who were recruited through convenience and snowball sampling via local libraries and youth centers, social media, and other public venues.

Participant milestones

Participant milestones
Measure	Control Active control - interaction with a stuffed dog only	Therapy Dog - Social animal-assisted intervention - social interaction only with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog	Therapy Dog - Social + Physical animal-assisted intervention - Social interaction and physical interaction with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog
Overall Study STARTED	25	25	25
Overall Study COMPLETED	25	25	25
Overall Study NOT COMPLETED	0	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Assessing Mechanisms of Anxiety Reduction in Animal-assisted Interventions

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Control - Interaction With a Stuffed Dog n=25 Participants Active control - interaction with a stuffed dog	Therapy Dog - Social n=25 Participants animal-assisted intervention - social interaction only with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog	Therapy Dog - Social + Physical n=25 Participants animal-assisted intervention - Social interaction and physical interaction with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog	Total n=75 Participants Total of all reporting groups
Age, Categorical <=18 years	25 Participants n=5 Participants	25 Participants n=7 Participants	25 Participants n=5 Participants	75 Participants n=4 Participants
Age, Categorical Between 18 and 65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Age, Continuous	15.4 years STANDARD_DEVIATION 1.4 • n=5 Participants	15.4 years STANDARD_DEVIATION 1.6 • n=7 Participants	15.7 years STANDARD_DEVIATION 1.4 • n=5 Participants	15.5 years STANDARD_DEVIATION 1.4 • n=4 Participants
Sex: Female, Male Female	17 Participants n=5 Participants	22 Participants n=7 Participants	7 Participants n=5 Participants	46 Participants n=4 Participants
Sex: Female, Male Male	8 Participants n=5 Participants	3 Participants n=7 Participants	18 Participants n=5 Participants	29 Participants n=4 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants	2 Participants n=7 Participants	2 Participants n=5 Participants	4 Participants n=4 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	25 Participants n=5 Participants	23 Participants n=7 Participants	23 Participants n=5 Participants	71 Participants n=4 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
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Race (NIH/OMB) Asian	3 Participants n=5 Participants	1 Participants n=7 Participants	2 Participants n=5 Participants	6 Participants n=4 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants
Race (NIH/OMB) White	22 Participants n=5 Participants	23 Participants n=7 Participants	20 Participants n=5 Participants	65 Participants n=4 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	0 Participants n=7 Participants	3 Participants n=5 Participants	3 Participants n=4 Participants
Race (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
Region of Enrollment United States	25 Participants n=5 Participants	25 Participants n=7 Participants	25 Participants n=5 Participants	75 Participants n=4 Participants
Social anxiety level Low Anxiety	8 Participants n=5 Participants	6 Participants n=7 Participants	4 Participants n=5 Participants	18 Participants n=4 Participants
Social anxiety level Mid Anxiety	7 Participants n=5 Participants	6 Participants n=7 Participants	9 Participants n=5 Participants	22 Participants n=4 Participants
Social anxiety level High Anxiety	10 Participants n=5 Participants	13 Participants n=7 Participants	12 Participants n=5 Participants	35 Participants n=4 Participants
Pet ownership	19 Participants n=5 Participants	17 Participants n=7 Participants	20 Participants n=5 Participants	56 Participants n=4 Participants

PRIMARY outcome

Timeframe: Self-reported anxiety was measured at six time points, during: (Time 1; 0 min) baseline, (Time 2; 30 min) anticipation, (Time 3; 35 min) preparation, (Time 4; 45 min) speech, (Time 5; 60 min) recovery period 1, and (Time 6; 75 min) recovery period 2.

Population: 7 participants were excluded due to protocol deviations (not following study directions), and 2 had missing data for self-reported affective experience.

Outcome measures

Outcome measures
Measure	Control - Stuffed Dog n=21 Participants active control: Interaction with a stuffed dog	Therapy Dog - Social n=20 Participants animal-assisted intervention - social interaction only with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog	Therapy Dog - Social + Physical n=25 Participants animal-assisted intervention - Social interaction and physical interaction with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog
Self-reported Affective Experience Time 2 - 30 min	8.33 units on a scale Standard Deviation 1.88	8.05 units on a scale Standard Deviation 1.32	7.88 units on a scale Standard Deviation 1.67
Self-reported Affective Experience Time 1 - 0 min	10.19 units on a scale Standard Deviation 1.81	10.00 units on a scale Standard Deviation 2.07	10.28 units on a scale Standard Deviation 1.60
Self-reported Affective Experience Time 3 - 35 min	12.05 units on a scale Standard Deviation 2.01	11.96 units on a scale Standard Deviation 2.44	12.36 units on a scale Standard Deviation 2.18
Self-reported Affective Experience Time 4 - 45 min	13.57 units on a scale Standard Deviation 2.40	13.14 units on a scale Standard Deviation 2.32	13.40 units on a scale Standard Deviation 2.40
Self-reported Affective Experience Time 5 - 60 min	9.33 units on a scale Standard Deviation 1.53	9.14 units on a scale Standard Deviation 1.93	8.68 units on a scale Standard Deviation 2.51
Self-reported Affective Experience Time 6 - 75 min	8.43 units on a scale Standard Deviation 1.43	8.52 units on a scale Standard Deviation 1.44	8.72 units on a scale Standard Deviation 2.01

SECONDARY outcome

Timeframe: Continuous through the 2 hour experiment.

Population: 7 participants were excluded for having a protocol deviation and 14 participants with EDA data that were not usable (3 of whom also had a protocol deviation)

Electrodermal activity (EDA) was recorded at 4 Hz by an Empatica E4 wristband sensor. EDA is reported in μSiemens with higher values representing higher levels of autonomic reactivity. EDA was recorded continuously, and for analysis was assessed over six time windows during the experiment: Time 1 = beginning of study; Time 2 = baseline period; Time 3 = anticipation phase; Time 4 = last 5 min of the stressor; Time 5 = recovery 1; Time 6 = recovery 2. Each time point was 5 minutes in duration.

Outcome measures

Outcome measures
Measure	Control - Stuffed Dog n=17 Participants active control: Interaction with a stuffed dog	Therapy Dog - Social n=20 Participants animal-assisted intervention - social interaction only with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog	Therapy Dog - Social + Physical n=20 Participants animal-assisted intervention - Social interaction and physical interaction with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog
Autonomic Physiological Reactivity: Electrodermal Activity	7.32 μSiemens Standard Deviation 3.03	6.56 μSiemens Standard Deviation 2.52	8.01 μSiemens Standard Deviation 3.41

SECONDARY outcome

Timeframe: continuous through the 2 hour experiment

Population: 7 participants were excluded due to protocol deviations (not following study directions).

Heart rate (beats per minute) Heart rate was measured via photoplethysmography from the Empatica E4 wristband using Empatica's proprietary algorithm, which automatically imputes missing data from the photoplethysmograph signal and corrects for motion artifacts. The heart rate is computed as the average heart rate values that spans 10 seconds. This average HR is computed at 1 Hz. HRwas recorded continuously, and for analysis was assessed over six time windows during the experiment: Time 1 = beginning of study; Time 2 = baseline period; Time 3 = anticipation phase; Time 4 = last 5 min of the stressor; Time 5 = recovery 1; Time 6 = recovery 2. Each time point was 5 minutes in duration.

Outcome measures

Outcome measures
Measure	Control - Stuffed Dog n=21 Participants active control: Interaction with a stuffed dog	Therapy Dog - Social n=22 Participants animal-assisted intervention - social interaction only with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog	Therapy Dog - Social + Physical n=25 Participants animal-assisted intervention - Social interaction and physical interaction with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog
Autonomic Reactivity: Heart Rate	79.48 Beats per minute Standard Deviation 7.92	78.73 Beats per minute Standard Deviation 10.55	80.44 Beats per minute Standard Deviation 11.36

SECONDARY outcome

Timeframe: 1 hour into 2 hour experiment

Population: 7 participants were excluded due to protocol deviations (not following study directions).

Number of errors (incorrect answer to subtraction task) during mental math task; better performance was characterized by fewer errors. Number of errors ranged from 0 to 8.

Outcome measures

Outcome measures
Measure	Control - Stuffed Dog n=21 Participants active control: Interaction with a stuffed dog	Therapy Dog - Social n=22 Participants animal-assisted intervention - social interaction only with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog	Therapy Dog - Social + Physical n=25 Participants animal-assisted intervention - Social interaction and physical interaction with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog
Cognitive Performance - Number of Errors	3.29 number of errors Standard Deviation 1.95	3.36 number of errors Standard Deviation 2.24	3.20 number of errors Standard Deviation 2.20

SECONDARY outcome

Timeframe: 1 hour into 2 hour experiment

Population: 7 participants were excluded due to protocol deviations (not following study directions)

Highest number of correct responses in serial subtraction task. To adjust for the different levels of subtraction based on age level, lowest number reached was operationalized by calculating the number of correct responses (a higher score indicating better performance). Number of correct answers ranged from 1 to 41.

Outcome measures

Outcome measures
Measure	Control - Stuffed Dog n=21 Participants active control: Interaction with a stuffed dog	Therapy Dog - Social n=22 Participants animal-assisted intervention - social interaction only with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog	Therapy Dog - Social + Physical n=25 Participants animal-assisted intervention - Social interaction and physical interaction with therapy dog during TSST. animal-assisted intervention: Interaction with a therapy dog
Cognitive Performance - Lowest Number Reached/Highest Number of Correct Responses	12.95 highest number of correct responses Standard Deviation 8.85	13.41 highest number of correct responses Standard Deviation 9.48	14.92 highest number of correct responses Standard Deviation 12.59

Adverse Events

Control

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Therapy Dog - Social

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Therapy Dog - Social + Physical

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

Dr. Megan K Mueller

Tufts University

Phone: 508-887-4543

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place