Alcoholism, clinical and experimental research 2017 10 28() doi 10.1111/acer.13540
Biomarkers can play a key role in supplementing self-report information in alcohol research. In this study, we examined phosphatidylethanol (PEth) in comparison to self-reported alcohol use over time in a randomized controlled trial.
MATERIALS AND METHODS
Participants were women living with HIV enrolled in a randomized placebo controlled trial of naltrexone for reducing hazardous drinking. Drinking behavior was measured using Timeline Followback (TLFB), and PEth as a biomarker using dried blood spots. Data collected at baseline, and months two and seven were analyzed. In addition to calculated Spearman’s correlations, mixed effects modeling was used to evaluate the changes in self-reported drinking and PEth respectively, adjusting for body mass index.
A total of 194 participants (83% black, mean age 48) were included in the analysis. PEth levels were significantly correlated with self-reported drinking via TLFB, Spearman’s r = .21, at baseline, r = .29 at 2- and r = .28 at 7-month, respectively. No demographic or health factors, except for BMI, was associated with whether self-report was consistent with PEth. Mixed effects model indicated that self-reported drinking showed significantly greater reductions in the naltrexone treatment group than the placebo group at the 2- and 7-month visits, whereas PEth measure only showed this difference at the 7-month follow-up.
The magnitude of the correlation between PEth and self-reported alcohol consumption was small. Caution is needed when using either self-report or PEth as a sole outcome measure for alcohol behavior changes in clinical trials. This article is protected by copyright. All rights reserved.