MACS/WIHS Combined Cohort Study (MWCCS) Administrative Supplement: Association of Alcohol Biomarkers with HIV and Clinical Outcomes Abstract: Fund Year 2020 OAR Strategic Funds are requested to perform an objective assessment of alcohol consumption in the MACS/WIHS Combined Cohort Study (MWCCS) by testing urine and blood specimens for ethyl glucuronide (EIG) and phosphatidylethanol (PEth), respectively. Specimens will be collected on existing MACS and WIHS participants who enroll into the MWCCS (n~4000) and in new MWCCS enrollees (n~1500) during CCS visits 101 and 102 in order to better characterize alcohol use and their associations with HIV outcomes (i.e., antiretroviral therapy [ART] adherence, viral suppression down to a single copy) and clinical outcomes (i.e., liver, cardiac, neurocognitive impairment). This supplement will support HIV/AIDS research that falls under the following NIH high priority AIDS-designated topics: 1) HIV-associated comorbidities ; and 2) cross-cutting areas including behavioral sciences, health disparities, and training of the next generation of HIV investigators in substance use and comorbidities research.