Factors associated with antiretroviral treatment interruptions among people living with HIV in British Columbia, Canada


BACKGROUND: Treatment interruptions (TI) limit the therapeutic protection offered by modern antiretroviral therapy (ART), thereby leading to poorer clinical outcomes and increased risk of HIV transmission. We evaluated factors associated with time-to-first TI among people living with HIV (PLWH) in British Columbia (BC), Canada.
METHODS: Between January 2016-September 2018, we purposively recruited a representative sample of PLWH aged '¥19 years in BC into the STOP HIV/AIDS Program Evaluation (SHAPE) study. Participants completed surveys at enrolment and followed through time with data linkages to the BC HIV Drug Treatment Program. Surveys collected sociodemographic information, drug use, homelessness, and incarceration history. TI were defined as >60 days late for ART refill and pharmacist-reviewed TI alert sent between enrolment and December 2020. We conducted bivariate analyses comparing baseline data from participants who did and did not experience TI. Multivariable Cox proportional hazards regression was used to model time-to-first TI.
RESULTS: Among 639 PLWH included in this analysis, 21.3% were women, 59.0% identified as men who have sex with men, 69.6% identified as Caucasian, and 15.5% self-identified as Indigenous. The median age at enrolment was 50 years (Q1-Q3:42-57) and median follow-up time was 4.15 years (Q1-Q3:2.98-4.65). Of 154 (24.1%) participants who experienced a TI since enrolment, the median time to their first TI was 15.9 months (Q1-Q3:8.1-29.3), and median length of their first TI was 96 days (Q1-Q3:76-154). We found a higher proportion of those reporting recent homelessness (64.3% vs. 45.4%; p<0.001), recent injection drug use (34.4% vs. 15.9%; p<0.001), food insufficiency (79.2% vs. 59.4%; p<0.001), lifetime violence (87.0% vs. 72.0%; p<0.001), and incarceration history (54.6% vs. 29.1%; p<0.001) experienced a TI during the study period. In the multivariable Cox model, lifetime experiences of incarceration (adjusted hazard ratio [aHR]:1.97, 95%CI:1.33-2.91) or violence (aHR:1.94, 95%CI:1.12-3.37) had increased risk of TI during study follow-up, while those aged '¥60 years (vs.<40; aHR:0.39, 95%CI:0.20-0.77), and greater than high school education (vs. less than high school; aHR:0.68, 95%CI:0.42-1.12) had a reduced risk.
CONCLUSIONS: We found lifetime experiences of incarceration or violence to be associated with TI, illustrating the impact of pervasive structural inequities across the life-course on ART treatment.

Download the e-Poster (PDF)