The Adherence Gap: A Longitudinal Examination of Men's and Women's Antiretroviral Therapy Adherence in British Columbia, 2000-2014

Objective: The aim of this study was to observe the effect of sex on attaining optimaladherence to combination antiretroviral therapy (cART) longitudinally while controllingfor known adherence confounders – IDU and ethnicity.Design: Using the population-based HAART Observational Medical Evaluation andResearch cohort, data were collected from HIV-positive adults, aged at least 19 years,receiving cART in British Columbia, Canada, with data collected between 2000 and2014. cART adherence was assessed using pharmacy refill data. The proportion ofparticipants reaching optimal (95%) adherence by sex was compared per 6-monthperiod from initiation of therapy onward. Generalized linear mixed models with logisticregression examined the effect of sex on cART adherence.Results: Among 4534 individuals followed for a median of 65.9 months (interquartilerange: 37.0–103.2), 904 (19.9%) were women, 589 (13.0%) were Indigenous, and1603 (35.4%) had a history of IDU. A significantly lower proportion of women relativeto men were optimally adherent overall (57.0 vs. 77.1%; P<0.001) and in covariateanalyses. In adjusted analyses, female sex remained independently associated withsuboptimal adherence overall (adjusted odds ratio: 0.55; 95% confidence interval:0.48–0.63).Conclusion: Women living with HIV had significantly lower cART adherence ratesthen men across a 14-year period overall, and by subgroup. Targeted research isrequired to identify barriers to adherence among women living with HIV to tailorwomen-centered HIV care and treatment support services.