Unhealthy alcohol use is very prevalent (22-30%) among persons with HIV (PWH), impairs adherence to antiretroviral therapy (ART), and fuels inflammation, HIV non-suppression, coinfections (e.g., tuberculosis), and noncommunicable diseases (NCDs) that are common among PWH. There is an urgent need to reduce unhealthy alcohol use, especially in Uganda which has high prevalence of HIV, unhealthy alcohol use, and HIV comorbidities. Brief (up to 4 hours) alcohol-focused interventions (BI) can reduce alcohol use in PWH, but their effect sizes have been modest. This is also true for screening and brief (5-15 minutes) interventions (SBI) that are being rolled out within HIV clinics in Uganda. BIs rely on self-reported alcohol consumption for assessment, personalized feedback, goal setting and monitoring, which are key for readiness and motivation for behavior change, but may be limited by impaired self-awareness and under-reporting. We hypothesize that alcohol biomarker testing and results communication, with a biomarker such as phosphatidylethanol (PEth), can improve the efficacy of BIs by increasing readiness and motivation for change via increased self-awareness and improved personalized feedback based on an objective measure, and by objectively measured goal setting and monitoring, similar to targeting a HbA1c level in diabetes, viral suppression in HIV, or tenofovir adherence in ART and HIV pre-exposure prophylaxis via recently developed urine testing. PEth is correlated with total prior month alcohol consumption and is sensitive and specific for unhealthy alcohol use; a low-cost PEth immunoassay is being validated, and a point-of-care test will likely soon follow. We propose the Phosphatidylethanol Results Communication (PERC) Study, that builds on our long-standing US/Uganda collaboration in alcohol/HIV research. Our long-term goal is to determine whether PEth can be used to boost the efficacy of alcohol BIs. Our short-term goal for this R34 is to develop the strategies to provide PEth results in BIs, and examine their acceptability, appropriateness, and feasibility, before proceeding to a larger trial. Aim 1 is to elicit input via a series of focus group discussions (FGDs) including theater testing and role playing, with several groups of stakeholders (patients, clinic staff, community, and government), and conduct field testing and in-depth interviews (IDIs) with PWH who engage in unhealthy alcohol use. Aim 2a is to conduct a pilot randomized controlled (RCT) trial (n=80), with PWH who engage in unhealthy alcohol use randomized to receive either PEth-boosted BI or the standard BI that is being rolled out in HIV care in Uganda. Our primary measures will be acceptability, appropriateness, and feasibility of the intervention, measured quantitatively and qualitatively. We will explore changes in readiness for alcohol reduction and changes in PEth at three months, by study arm. Lastly, we will share these results in FGDs with the stakeholders from Aim...