Trial Outcomes & Findings for Feasibility and Acceptability of Digital Pills to Monitor PrEP Adherence in MSM With Substance Use (NCT NCT03842436)

NCT ID: NCT03842436

Last Updated: 2022-12-22

Results Overview

Participants' engagement with the digital pill system (DPS) was measured over the 90-day study period. The percentages for the total expected ingestions recorded by DPS each month were compared.

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

16 participants

Primary outcome timeframe

Months 1, 2, and 3

Results posted on

2022-12-22

Participant Flow

Participant milestones

Participant milestones
Measure
Digital Pills
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Overall Study
STARTED
16
Overall Study
COMPLETED
15
Overall Study
NOT COMPLETED
1

Reasons for withdrawal

Reasons for withdrawal
Measure
Digital Pills
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Overall Study
Lost to Follow-up
1

Baseline Characteristics

One participant was lost to follow-up.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Digital Pills
n=15 Participants
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Age, Continuous
32 years
n=15 Participants • One participant was lost to follow-up.
Sex: Female, Male
Female
0 Participants
n=15 Participants • One participant was lost to follow-up.
Sex: Female, Male
Male
15 Participants
n=15 Participants • One participant was lost to follow-up.
Ethnicity (NIH/OMB)
Hispanic or Latino
4 Participants
n=15 Participants • One participant was lost to follow-up.
Ethnicity (NIH/OMB)
Not Hispanic or Latino
11 Participants
n=15 Participants • One participant was lost to follow-up.
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=15 Participants • One participant was lost to follow-up.
Race/Ethnicity, Customized
Race · White
10 Participants
n=15 Participants • One participant was lost to follow-up.
Race/Ethnicity, Customized
Race · Black / African American
1 Participants
n=15 Participants • One participant was lost to follow-up.
Race/Ethnicity, Customized
Race · Asian
1 Participants
n=15 Participants • One participant was lost to follow-up.
Race/Ethnicity, Customized
Race · More than one race
2 Participants
n=15 Participants • One participant was lost to follow-up.
Race/Ethnicity, Customized
Race · Other
1 Participants
n=15 Participants • One participant was lost to follow-up.
Region of Enrollment
United States
15 Participants
n=15 Participants • One participant was lost to follow-up.
Education
Some college
2 Participants
n=15 Participants • One participant was lost to follow-up.
Education
College degree
7 Participants
n=15 Participants • One participant was lost to follow-up.
Education
Graduate degree/professional
6 Participants
n=15 Participants • One participant was lost to follow-up.
Sexual Orientation
Homosexual or gay
13 Participants
n=15 Participants • One participant was lost to follow-up.
Sexual Orientation
Bisexual
2 Participants
n=15 Participants • One participant was lost to follow-up.
STI in prior 12 month
Yes
10 Participants
n=15 Participants • One participant was lost to follow-up.
STI in prior 12 month
No
5 Participants
n=15 Participants • One participant was lost to follow-up.
Reported substance use
Alcohol
14 Participants
n=15 Participants • One participant was lost to follow-up.
Reported substance use
Marijuana
10 Participants
n=15 Participants • One participant was lost to follow-up.
Reported substance use
Stimulants
7 Participants
n=15 Participants • One participant was lost to follow-up.
Reported substance use
Hallucinogens
4 Participants
n=15 Participants • One participant was lost to follow-up.
Reported substance use
Other (poppers, amyl nitrate)
7 Participants
n=15 Participants • One participant was lost to follow-up.
Prescribed PrEP
Yes
14 Participants
n=15 Participants • One participant lost to follow-up.
Prescribed PrEP
No
1 Participants
n=15 Participants • One participant lost to follow-up.
Nonadherent to PrEP in prior 2 weeks (self-report)
Yes
3 Participants
n=14 Participants • One participant was lost to follow-up. Additionally, the denominator for this variable is 14, as 14 participants had already been prescribed PrEP, and one had not.
Nonadherent to PrEP in prior 2 weeks (self-report)
No
11 Participants
n=14 Participants • One participant was lost to follow-up. Additionally, the denominator for this variable is 14, as 14 participants had already been prescribed PrEP, and one had not.

PRIMARY outcome

Timeframe: Months 1, 2, and 3

Population: One participant was temporarily lost to follow-up, so they were excluded from analysis. In Month 1, the total number of DPS-recorded ingestion events (411) exceeded the total expected ingestion events from pill counts (402), as a result of one participant returning nine more unused pills than anticipated at the end of the month. The total expected ingestions for Month 1 is listed as 411 in the table below for clarity.

Participants' engagement with the digital pill system (DPS) was measured over the 90-day study period. The percentages for the total expected ingestions recorded by DPS each month were compared.

Outcome measures

Outcome measures
Measure
Digital Pills
n=1192 Expected ingestions per pill counts
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Feasibility of Digital Pills to Measure PrEP Adherence
Month 1: Total ingestions recorded by DPS
411 Expected ingestions per pill counts
Feasibility of Digital Pills to Measure PrEP Adherence
Month 2: Total ingestions recorded by DPS
368 Expected ingestions per pill counts
Feasibility of Digital Pills to Measure PrEP Adherence
Month 3: Total ingestions recorded by DPS
320 Expected ingestions per pill counts

SECONDARY outcome

Timeframe: Months 1, 2, and 3

Population: One participant was temporarily lost to follow-up.

The total number recorded ingestions recorded by the digital pill system (DPS) - which included both the number of Reader-detected and manually-reported ingestions - was collected. The Reader-detected ingestions count was used to reflect the number of times the DPS was operated correctly. Successful DPS operation was defined as ingestion of a digital pill, proper use of the wearable Reader, and confirmation of the ingestion on both the Reader and the app. Cumulative data collected at months 1, 2, and 3 are reported in the data table below.

Outcome measures

Outcome measures
Measure
Digital Pills
n=1099 Recorded ingestions
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Digital Pill Performance - Number of Recorded Ingestions
Reader-detected ingestions
922 Recorded ingestions
Digital Pill Performance - Number of Recorded Ingestions
Manually reported ingestions
177 Recorded ingestions

SECONDARY outcome

Timeframe: Months 1, 2, and 3

Population: One participant was temporarily lost to follow-up, so they were excluded from the analysis.

Accuracy of the digital pill system (DPS) in measuring PrEP adherence. To analyze the performance of the DPS, the ground truth of PrEP ingestion events was defined as the pill counts obtained each month (i.e., the number of unused pills returned, subtracted from the number of pills previously dispensed). The number of DPS-recorded ingestions - which included the number of both Reader-detected and manually-reported ingestions - was compared with the aggregate pill count at each monthly timepoint; this was defined as the overall performance metric for the DPS. Cumulative data collected at months 1, 2, and 3 are reported in the data table below.

Outcome measures

Outcome measures
Measure
Digital Pills
n=1192 Expected ingestions based on pill counts
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Digital Pill Performance - System Accuracy
92 percentage of ingestions DPS recorded
Interval 91.0 to 94.0

SECONDARY outcome

Timeframe: Months 1, 2, and 3

Population: One participant was temporarily lost to follow-up.

The total number of manually reported ingestions was collected. The percentages for instances of manually reported ingestions were calculated. The two instances for manually recording ingestions included, a lack of engagement with the Reader or failure to use the Reader properly, and when reported ingestion was not detected by the Reader despite supporting use metrics indicating proper Reader use. Cumulative data collected at months 1, 2, and 3 are reported in the data table below.

Outcome measures

Outcome measures
Measure
Digital Pills
n=177 Manually-reported ingestions
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Digital Pill Performance - Manually Reported Ingestions
Lack of engagement with the Reader or failure to use Reader properly
158 Manually-reported ingestions
Digital Pill Performance - Manually Reported Ingestions
Instances where reported ingestion was not detected by the Reader despite proper Reader use
19 Manually-reported ingestions

SECONDARY outcome

Timeframe: Months 1, 2, and 3

Population: One participant was temporarily lost to follow-up.

The total number of instances in which ingestions were successfully detected by the Reader (i.e., the radio frequency emitter was activated, and the ingestion was recorded by the DPS) was collected. The total number of instances in which manually reported ingestions were not detected by the Reader, despite supporting use metrics (e.g., accelerometer data) indicating proper Reader use was also collected. These counts were combined and interpreted as the number of times that the DPS was operated correctly. Cumulative data collected at months 1, 2, and 3 are reported in the data table below.

Outcome measures

Outcome measures
Measure
Digital Pills
n=941 Ingestions successfully detected by DPS
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Digital Pill Performance - Successful Operation of System
Reader-detected digital pill ingestions that activated radio frequency emitter
922 Ingestions successfully detected by DPS
Digital Pill Performance - Successful Operation of System
Manually reported digital pill ingestions with supporting use metrics indicating proper Reader use
19 Ingestions successfully detected by DPS

SECONDARY outcome

Timeframe: Months 1 and 3

We dichotomized TFV-DP levels using a cutoff of ≥700 fmol/punch to indicate at least four doses of PrEP ingested per week. Using TFV-DP in DBS \<700 vs ≥700 fmol/punch as a dichotomous variable, and considering the granular continuous adherence data from the digital pill, we then calculated a point biserial correlation between TFV-DP in DBS and digital pill adherence. Additionally, drug concentrations of tenofovir diphosphate as measured in dried blood spot collection at months one and three were compared to DPS-recorded PrEP adherence.

Outcome measures

Outcome measures
Measure
Digital Pills
n=22 Paired DBS samples
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Dried Blood Spot Correlation With Digital Pill Adherence
Point-biserial correlation
0.58 correlation coefficient
Interval 0.21 to 0.8
Dried Blood Spot Correlation With Digital Pill Adherence
Pearson's correlation for month one
0.85 correlation coefficient
Interval 0.57 to 0.95
Dried Blood Spot Correlation With Digital Pill Adherence
Pearson's correlation for month three
0.75 correlation coefficient
Interval 0.17 to 0.94

OTHER_PRE_SPECIFIED outcome

Timeframe: Month 3

Population: Qualitative user experience data were collected via interviews from the 15 participants who completed the study.

Acceptability was assessed via individual, semi-structured, qualitative exit interviews conducted at the end of the 90-day study period. The qualitative interview guide was grounded in the Technology Acceptance Model. Questions explored participants' experiences using the digital pill system (DPS), including facilitators and barriers to use, engagement with the technology, and willingness to use the DPS long-term.

Outcome measures

Outcome measures
Measure
Digital Pills
n=15 Participants
Digital Pills containing Truvada ingested once daily as PrEP Digital pill: Digital pills over encapsulating Truvada Truvada: Truvada prescribed with digital pills for PrEP
Number of Participants That Completed Qualitative Interview to Evaluate Acceptability of Digital Pills
15 Participants

Adverse Events

Digital Pills

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

Peter R. Chai, MD, MMS

Brigham and Women's Hospital

Phone: 617-732-5640

Results disclosure agreements

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