Project Summary Background. The number of older people living with HIV (PLWH) in the U.S. is growing rapidly. Half of PLWH in 2016 were over 50 years of age, with an estimate of 70% by 2030. PLWH have high numbers of comorbidities, polypharmacy and high hospitalization rates. The transitions between care settings (e.g., home, hospital, post-acute care, and long-term care) that necessarily occur for PLWH who are aging – and the quality of care problems that these transitions create – are the focus of this proposal. Previous studies in the general aging population show that problems with medications are common after a hospitalization; approximately one fourth did not fill new prescriptions,14% experienced medication discrepancies and almost half were not adherent to medications following hospitalizations. There is limited data about medication-related quality problems following hospitalization for PLWH. In a recent study, only 64% of the study patients in the nursing homes (NHs) used ART. Our preliminary work with Medicare recipients has shown that about two thirds of a national cohort of NH residents with Part D (Medicare drug coverage) and HIV did not receive an ART during an average of 1 years of observation in NHs. The purposes of this proposed research are to (1) determine patterns of ART use in PLWH who made the care transition from outpatient status to NH care; and (2) identify patient level characteristics and nursing facility characteristics that are associated with the lack of ART use during NH stays following hospital discharge transitions. Methods. We propose to conduct a retrospective cohort study including all Medicare fee-for-service NH residents (2014-2018) nationally. First, we will identify PLWH who had an acute hospitalization that led to a NH admission. We will follow them to examine ART use during post-hospital discharge NH stays, and follow them backward in time to the prehospital period to determine whether they were on ART as outpatients. We will conduct multivariable models to determine correlates of non-ART use following the care transition. Covariates will include individual level characteristics, such as demographics, polypharmacy, comorbidity status, hospitalization length of stay and diagnosis; and nursing facility level characteristics such as HIV concentration, the availability of an AIDS unit and county level HIV prevalence as a proxy of provider HIV experience. Expected findings and future plans. We expect to observe that a reduction in ART use following the hospital discharge transition to NHs. ART use is a critical element of high-quality HIV care, and we are concerned that dropping of an ART regimen at NHs is a marker or indicator of broader quality of care problems. Our study will identify a clear focus for quality improvement interventions to ensure that PLWH in NHs (absent contraindications) are using ART. Our methods will also be used to conduct similar studies to ensure that other medications for chronic co...