Self-reported alcohol use versus phosphatidylethanol in behavioral trials: A study of people living with HIV in Tshwane, South Africa.

Abstract

Accurately quantifying alcohol use among persons with HIV (PWH) is important for validly assessing the efficacy of alcohol reduction interventions. We used data from a randomized controlled trial of an intervention to reduce alcohol use among PWH who were receiving antiretroviral therapy in Tshwane, South Africa. We calculated agreement between self-reported hazardous alcohol use measured by the Alcohol Use Disorders Identification Test (AUDIT; score ≥8) and AUDIT-Consumption (AUDIT-C; score ≥3 for females and ≥4 for males), heavy episodic drinking (HED) in the past 30 days, and heavy drinking in the past 7 days with a gold standard biomarker--phosphatidylethanol (PEth) level (≥50 ng/mL)--among 309 participants. We used multiple logistic regression to assess whether underreporting of hazardous drinking (AUDIT-C vs. PEth) differed by sex, study arm, and assessment time point. Participants' mean age was 40.6 years, 43% were males, and 48% were in the intervention arm. At 6 months, 51% had PEth ≥50 ng/mL, 38% and 76% had scores indicative of hazardous drinking on the AUDIT and AUDIT-C, respectively, 11% reported past 30-day HED, and 13% reported past 7-day heavy drinking. At 6 months, there was low agreement between AUDIT-C scores and past 7-day heavy drinking relative to PEth ≥50 (sensitivities of 83% and 20% and negative predictive values of 62% and 51%, respectively). Underreporting of hazardous drinking at 6 months was associated with sex (OR = 3.504. 95% CI: 1.080 to 11.364), with odds of underreporting being greater for females. Steps should be taken to decrease underreporting of alcohol use in clinical trials.