Self-reported and Point-of-Care Biomarkers of Substance Use Measures Among Older Adults with HIV from Low- and Middle-Income Countries.

Measuring alcohol and other drug (AOD) use remains challenging in HIV care in low- and middle-income countries, where self-report and point-of-care (POC) urine biomarkers capture different time windows. Among 2,059 people with HIV aged 40 years or older across eight IeDEA clinics (2020 to 2022), we examined what self-reported AOD use (AUDIT, ASSIST) and POC urine tests (uEtG for alcohol; 5-panel drug screen) each capture. Self-report identified more use than urine testing (unhealthy alcohol 19.7% versus uEtG-positive 12.2%), consistent with its longer recall window. Higher self-reported alcohol intensity was associated with uEtG positivity in a graded pattern, more strongly among women. Urine-positive but self-report-negative results, more common among men, suggested under-reporting. Self-report and biomarkers answer different measurement questions: self-report for longer-term burden and screening, biomarkers for recent use and corroboration. Combining both, including longer-window biomarkers, can strengthen AOD measurement among older PWH in LMICs.