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Activity Number:
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417
- Contributed Poster Presentations: Section on Statistics in Epidemiology
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Type:
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Contributed
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Date/Time:
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Tuesday, August 1, 2017 : 2:00 PM to 3:50 PM
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Sponsor:
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Section on Statistics in Epidemiology
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Abstract #322447
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Title:
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Estimating the Protective Effect of Longitudinal DrugConcentration in Pre-Exposure Prophylaxis for HIV Prevention
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Author(s):
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Claire Ruberman* and Jon Steingrimsson and Michael Rosenblum and Craig Hendrix
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Companies:
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Johns Hopkins University and Johns Hopkins University and Johns Hopkins University and Johns Hopkins School of Medicine
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Keywords:
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Targeted Maximum Likelihood Estimation ;
HIV prevention ;
Pre-exposure prophylaxis ;
Causal Inference ;
Marginal structural models ;
Nested case-cohort study
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Abstract:
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Pre-exposure prophylaxis (PrEP) is a promising tool for HIV prevention. Randomized controlled trials estimating the prevention effect of PrEP have shown varying effect sizes; this difference has been partially attributed to differences in medication adherence. We employ targeted maximum likelihood estimation (TMLE) \citep{van2006targeted} to account for adherence while estimating the effect of longitudinal drug concentration on protection against HIV infection based on three randomized PrEP trials: VOICE, Partners PrEP, and the Pre-exposure Prophylaxis Initiative (iPrEx). We estimate HIV infection rates had the trial populations all been set to high or low concentration throughout the trial and define the treatment effect as the causal effect of setting blood tenofovir concentration to be sustained above versus below a threshold concentration throughout the trial on the risk of HIV infection. We find similar treatment effects in the the Partners PrEP and iPrEx trials as previous analyses, but find PrEP to have a substantially stronger treatment effect in the oral dosing arm of the VOICE study than previous analyses suggest.
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Authors who are presenting talks have a * after their name.
