Biomarkers for Alcohol/HIV Research (BAHR) Study - ABSTRACT
Alcohol use is common among people living with HIV (PWH) and is a consistent predictor of poor antiretroviral
therapy (ART) adherence. It has also been associated with HIV virologic failure and mortality, but these results
have been somewhat mixed and the relationships between level of alcohol use and these outcomes are not
well defined. Interventions to reduce alcohol use among PWH have shown modest or mixed results. Thus, the
level of alcohol use needed to cause harm for PWH and the efficacy of interventions to reduce the harm are
uncertain. This uncertainty stems in part from the near ubiquitous reliance on self-report to measure alcohol
use, which may be inaccurate due to recall bias or social desirability bias and lead to spurious or obscured
results, and from inconsistent alcohol measurement. Objective biomarkers can be leveraged to supplement
self-report or as alternatives to self-report. The leading alcohol biomarker is phosphatidylethanol (PEth), which
can be found in whole blood or dried blood spots, detects prior 2-4 weeks alcohol use, and is correlated with
total alcohol consumed. Several research studies of PWH have conducted or plan to conduct PEth testing,
making possible an unprecedented opportunity to pool a large number of observations with PEth and HIV data
to provide definitive answers to these questions. We propose the Biomarkers for Alcohol/HIV Research
(BAHR) Study to gather and pool these data, which will include more than 8,000 PWH with 15,000
observations, and use PEth to resolve past alcohol/HIV research uncertainties, to guide future interventions,
and to provide measurement guidance for future research. We will determine the relationship between PEth-
measured alcohol use and HIV virologic failure and mortality risk among PWH who are on ART using data from
six studies (Aim 1). We will conduct individual participant data meta-analyses of alcohol/HIV intervention
studies (15 have agreed to participate) to examine evidence of the efficacy of the interventions to reduce PEth-
measured alcohol use, and their further impact on virologic failure (Aim 2). For both these aims, we will
compare the results using PEth alone to those obtained using self-report alone, and self-report combined with
PEth, to guide future alcohol measurement in research. Lastly, because PEth is expensive and inaccessible in
low-resource and non-research settings, we will examine the predictive value of a combination of common
laboratory tests as a low-cost alternative to PEth testing, leveraging the extensive testing being conducted in a
6000-person study (Aim 3). These analyses will provide tangible advancements for the alcohol/HIV field,
namely definitive answers on the relationship of alcohol use to HIV virologic failure and mortality risk; the
efficacy of alcohol interventions studies to reduce alcohol use and decrease virologic failure; information on
the comparability of results using biomarkers versus self-report to measure alcohol use; and evidence on
the predictive ability of a low-cost alcohol risk score for further testing and potential increased availability in
low-resource and non-research settings.