User Experience of Persons Using Ingestible Sensor–Enabled Pre-Exposure Prophylaxis to Prevent HIV Infection: Cross-Sectional Survey Study

Background: The success or failure of a digital health technology depends upon how it is received by the user. Objective: We conducted a detailed evaluation of user experience (UX) amongst persons who utilized an FDA-approved digital health feedback system (DHFS) incorporating ingestible sensors (IS) to capture medication adherence, after they were prescribed oral pre-exposure prophylaxis (PrEP) to prevent HIV infection. We then performed an association analysis with individual participant characteristics captured at baseline, to see if ‘personas’ associated with positive or negative UX emerged. Methods: UX data was collected upon exit from a prospective intervention study of HIV-negative adults prescribed oral PrEP who used the DHFS with ingestible sensor-enabled tenofovir disoproxil fumarate plus emtricitabine (IS-Truvada®). Baseline demographics, urine toxicology, and self-report questionnaires evaluating sleep (PSQI), self-efficacy, habitual self-control, HIV risk perception (PRHS 8-item), and depressive symptoms (PHQ-8) were obtained. Participants with ≥ 28 days on study completed a Likert-scale UX questionnaire of 27 questions grouped into 4 domain categories: Overall Experience, Ease of Use, Intention of Future Use, and Perceived Utility. Averages and interquartile range (IQR) were computed for participant total and domain sub-scores, and mixed-effects logistic regression modeled baseline participant characteristics associated with UX responses. Demographic characteristics of participants who responded to the questionnaire versus non-responders were compared using Fisher’s exact test. Results: Seventy-one participants enrolled with a mean age of 37.6 years (range 18-69), 90.1% male, 77.5% white, 33.8% Hispanic, 95.8% housed and 74.6% employed. No difference in demographics were observed in the 63 participants who persisted on the intervention for ≥28 days. Participants completing the detailed exit UX questionnaire (n= 53) were housed (98.1% vs 80%; p=0.063) and less likely to have a positive urine toxicology (35.3% vs 70%; p=0.075), particularly with methamphetamine (7.8% vs 40%; p=0.020), than non-completers (n=10). Based on IQR values 75% of participants had favorable UX with Total Score (IQR 3.17-4.20), mean(SD) 3.74 (0.70); Overall Experience (IQR 3.50-4.50), mean (SD) 3.89 (0.87); Ease of Use (IQR 3.33-4.22), mean (SD)=3.74 (0.65); and Perceived Utility (IQR 3.22-4.25), mean (SD)=3.73 (0.76). At least 50% of participants expressed Intention of Future Use (median=3.80, IQR 2.80-4.40). Following multi-predictor modeling self-efficacy was significantly associated with the total score 0.822 (0.405. 1.240) p<0.001, and all sub-scores. Persons with more depressive symptoms reported better perceived utility, worse PHQ-8 score natural cubic spline with 3 knots, overall p=0.013. Poor sleep was associated with a worse overall experience, per point PSQI -0.07 (-0.133, -0.006) P<0.032. Conclusions: User Experience amongst persons using ingestible sensor-enabled PrEP (IS-Truvada®) to prevent HIV infection was positive. Association analysis of participant characteristics at baseline, identified higher self-efficacy was associated with positive UX experience, more depressive symptoms with higher perceived utility, and poor sleep with negative UX experience. Clinical Trial: ClinicalTrials.gov NCT03693040; https://clinicaltrials.gov/study/NCT03693040