HIV pre-exposure prophylaxis (PrEP) effectiveness depends on adherence, which requires retention in PrEP care. We examined factors associated with PrEP adherence and retention among at-risk cisgender women prescribed oral PrEP.
Adherence Enhancement Guided by Individualized Texting and Drug Levels (AEGiS) was a 48-week single-arm open-label demonstration study of daily oral tenofovir disoproxil fumarate/emtricitabine in cisgender women ?18 years old at risk for HIV conducted at five Southern California sites. Study visits occurred at baseline and at weeks 4, 12, 24, 36 and 48. Adherence was supported with text messages and titrated adherence counseling based on rapid-turnaround tenofovir diphosphate (TFV-DP) concentrations from dried blood spots. Adherence was examined in four ways: (a) having any TFV-DP ?4 doses per week (d/w), (b) having any TFV-DP ?6 d/w, (c) having all TFV-DP ?4 d/w, and (d) having all TFV-DP ?6 d/w at all visits attended. Retention was defined as completing the week 48 visit. We used univariate and multivariable logistic regression to identify baseline demographic and sociobehavioral predictors associated with adherence and retention.
From June 2016 to October 2018, 136 cisgender women enrolled [mean age 40yo (SD 11); 38% non-Hispanic Black and 19% Latina]. In univariate analyses, cisgender Black vs non-Black women (58%, 30%, p=0.003), those attending LA vs San Diego site (79%, 58%, p=0.017) and those having partners of unknown risk vs a partner living with HIV (48%, 25%, p=0.012) were less likely to have consistent TFV-DP ?4 d/w (findings similar for consistent TFV-DP 6 d/w). However, only Black race (OR 0.37, p=0.014) and having partners of unknown risk (OR 0.36, p=0.02) with all TFV-DP ?4 d/w remained significantly associated in the multivariable analysis (see Forest Plot for all adherence outcomes). In univariate analyses, severe drug abuse on the DAST-10 (19%, 5%, p=0.031) was associated with lower likelihood of retention and interest in becoming pregnant in the next 6 months (13%, 32%, p=0.03) with greater likelihood of retention. Only pregnancy interest remained significant in multivariable models (OR 2.81, p=0.042).
In this cohort of cisgender women on PrEP, race and HIV risk group affected adherence whereas severe drug use negatively, and desire to become pregnant positively, impacted retention. Larger prospective studies should evaluate factors associated with long-term adherence and engagement in real-world PrEP settings.