ArticleAmerican journal of epidemiology2013
Estimating the efficacy of preexposure prophylaxis for HIV prevention among participants with a threshold level of drug concentration.
Article in American journal of epidemiology, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers, 1 of them a synthesis that pooled it.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
16 citing papers in PubMed, 1 synthesis or guideline pooled it.
- A systematic review of interventions to reduce HIV-related stigma and discrimination from 2002 to 2013: how far have we come?Journal of the International AIDS Society · 2013Pooled it
- Estimating efficacy in a randomized trial with product nonadherence: application of multiple methods to a trial of preexposure prophylaxis for HIV prevention.American journal of epidemiology · 2015Trial
- Patterns and correlates of PrEP drug detection among MSM and transgender women in the Global iPrEx Study.Journal of acquired immune deficiency syndromes (1999) · 2014Trial
- Preferences and Acceptability of Vaginal Delivery Forms for HIV Prevention Among Women, Male Partners and Key Informants in South Africa and Zimbabwe: Qualitative Findings.AIDS and behavior · 2021Article
- Mosaic effectiveness: measuring the impact of novel PrEP methods.The lancet. HIV · 2019Review
- The Connection between the Averted Infections Ratio and the Rate Ratio in Active-control Trials of Pre-exposure Prophylaxis Agents.Statistical communications in infectious diseases · 2019Article
- Weighing the Evidence of Efficacy of Oral PrEP for HIV Prevention in Women in Southern Africa.AIDS research and human retroviruses · 2018Review
- Modernizing Field Services for Human Immunodeficiency Virus and Sexually Transmitted Infections in the United States.Sexually transmitted diseases · 2017Review
- Modeling HIV vaccine trials of the future.Current opinion in HIV and AIDS · 2016Review
- Pharmacological Measures of Treatment Adherence and Risk of HIV Infection in the VOICE Study.The Journal of infectious diseases · 2016Article
- Measuring the potential role of frailty in apparent declining efficacy of HIV interventions.HIV clinical trials · 2015Article
- Clinical Treatment Options Infectious Diseases: Update on PrEP Implementation, Adherence, and Advances in Delivery.Current treatment options in infectious diseases · 2015Article
- Article
- Editorial: Global action to reduce HIV stigma and discrimination.Journal of the International AIDS Society · 2013Article
- In pursuit of an HIV vaccine: designing efficacy trials in the context of partially effective nonvaccine prevention modalities.AIDS research and human retroviruses · 2013Article
- Intravaginal rings as delivery systems for microbicides and multipurpose prevention technologies.International journal of women's health · 2013Review
Corrections and comments
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Authors and funding
4 authors.
Funding
Abstract
Assays for detecting levels of antiretroviral drugs in study participants are increasingly popular in preexposure prophylaxis (PrEP) trials, since they provide an objective measure of adherence. Current correlation analyses of drug concentration data are prone to bias. In this article, we formulate the causal estimand of prevention efficacy among drug compliers, those who would have had a threshold level of drug concentration had they been assigned to the drug arm of the trial. The identifiability of the causal estimand is facilitated by exploiting the exclusion restriction; that is, drug noncompliers do not acquire any prevention benefit. In addition, we develop an approach to sensitivity analysis that relaxes the exclusion restriction. Applications to published data from 2 PrEP trials, namely the Preexposure Prophylaxis Initiative (iPrEx) trial and the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 trial, suggest high efficacy estimates among drug compliers (in the iPrEx trial, odds ratio = 0.097 (95% confidence interval: 0.027, 0.352); in the CAPRISA 004 trial, odds ratio = 0.104 (95% confidence interval: 0.024, 0.447)). In summary, the proposed inferential method provides an unbiased assessment of PrEP efficacy among drug compliers, thus adding to the primary intention-to-treat analysis and correlation analyses of drug concentration data.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.