Antiretroviral therapy use, self-reported adherence, and viral suppression among women living with HIV in Canada

Background: Traditionally, ≥95% adherence was recommended for viral suppression (VS). Newer antiretroviral therapy (ART) is now being increasingly prescribed and may be more forgiving of lower adherence. The lifelong nature of ART presents adherence challenges, particularly for women living with HIV. We aimed to describe ART use and examine the association between adherence and VS. Methods: The Canadian HIV Women's Sexual and Reproductive Health Cohort, which included 1422 participants, was used. Data was collected three times, at 18-month intervals, between 2013 and 2018. A Sankey diagram illustrated longitudinal ART trends among participants who reported their ART use. Cross-sectional analysis using 2017–2018 data included participants who self-reported their regimen, ART adherence, and viral load. Utilizing logistic regression models, self-reported adherence (percentage of ART taken in the past month) and self-reported VS (most recent <50 copies/mL) were investigated. Results: Among participants reporting ART use (n = 1187), integrase inhibitor use increased from 13.6% (n = 162) to 30.6% (n = 363), while other classes decreased. Among 617 participants assessed between 2017 and 2018, <70% adherence levels (adjusted odds ratio [aOR]: 0.06, 95% confidence interval [CI]: 0.01–0.27), 70%–79% adherence (aOR: 0.29, 95% CI: 0.05–1.77) and 80%–89% (aOR: 0.21, 95% CI: 0.05–0.86) were associated with lower odds of reporting VS compared with ≥95% adherence, although statistically not significant for 70%–79% adherence. No difference was found for 90%–94% adherence (aOR: 1.04, 95% CI: 0.20–5.32) compared with ≥95%. Conclusion: Our findings suggest that ART adherence levels lower than 90% are associated with a lower likelihood of VS among women living with HIV.