1. Efficacy of the Dapivirine Vaginal Ring Accounting for Imperfect Adherence.
- Author
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Husnik, Marla J., Heffron, Renee, Hughes, James P., Richardson, Barbra, van der Straten, Ariane, Palanee-Phillips, Thesla, Soto-Torres, Lydia, Singh, Devika, Mirembe, Brenda Gati, Livant, Edward, Gaffoor, Zakir, Mansoor, Leila E., Siva, Samantha S., Dadabhai, Sufia, Kiweewa, Flavia Matovu, and Baeten, Jared M.
- Subjects
HIV prevention ,PATIENT compliance ,COCHLEAR implants ,STATISTICAL models ,ANTIRETROVIRAL agents ,RESEARCH funding ,STRUCTURAL models ,HIV infections ,DESCRIPTIVE statistics ,DRUG delivery systems ,PRE-exposure prophylaxis ,DRUG efficacy ,CERVICAL caps ,WOMEN'S health ,EVALUATION - Abstract
Product adherence is critical to obtaining objective estimates of efficacy of pre-exposure prophylactic interventions against HIV-1 infection. With imperfect adherence, intention-to-treat analyses assess the collective effects of complete, sub-optimal and non-adherence, providing a biased and attenuated estimate of the average causal effect of an intervention. Using data from the MTN-020/ASPIRE phase III trial evaluating HIV-1 efficacy of the dapivirine vaginal ring, we conducted per-protocol, and adherence-adjusted causal inference analyses using principal stratification and marginal structural models. We constructed two adherence cut offs of ≥ 0.9 mg (low cutoff) and > 4.0 mg (high cutoff) that represent drug released from the ring over a 28-day period. The HIV-1 efficacy estimate (95% CI) was 30.8% (3.6%, 50.3%) (P = 0.03) from the per-protocol analysis, and 53.6% (16.5%, 74.3%) (P = 0.01) among the highest predicted adherers from principal stratification analyses using the low cutoff. Marginal structural models produced efficacy estimates (95% CIs) ranging from 48.8 (21.8, 66.4) (P = 0.0019) to 56.5% (32.8%, 71.9%) (P = 0.0002). Application of adherence-adjusted causal inference methods are useful in interpreting HIV-1 efficacy in secondary analyses of PrEP clinical trials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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