Clinical and Epidemiological Analyses of Mental Illness, Substance Use and Health Outcomes of People Living with HIV in Texas

Objectives: Mental illness and substance use have been linked to poor outcomes in chronic diseases including HIV. We aimed to describe the burden of mental illness and substance use among people living with HIV in Texas, assess the impact on viral suppression and CD4 count, and develop a prediction model to predict the risk of having sub-optimal HIV clinical outcome. Methods: The 2015-2019 Texas Medical Monitoring Project (MMP) data was used. Descriptive analyses were conducted to describe patient characteristics, health behavior, and environmental factors. Multivariable logistic regression was used to assess associations between mental illness, substance use, and HIV outcomes, as well as to obtain a prediction model for assessing the risk of sub-optimal HIV outcome. The final prediction model was internally validated using 500 bootstraps. Risk score points were assigned to each risk predictors based on their respective beta coefficients. Results: We identified knowledge gaps on the impact of mental illness and substance use on HIV outcomes among people living with HIV in Texas. In aim 2, a total of 1665 respondents representing 85,354 adults living with HIV in Texas were included. Majority of the participants (78.8%) had mental illness or substance use problems. Substance use only was associated with not being virally suppressed (aOR 1.65, 95% CI 1.06-2.56, p=0.0279). In aim 3, a total of 518 respondents representative of 27,255 adults living with HIV and diagnosed mental illness or substance use disorders in Texas were included. The prediction model had an area under the receiver-operating characteristic curve (AUC) of 0.727, and contained 8 risk predictors: mental illness and substance use disorders severity, retention in care, adherence, health insurance coverage gaps, healthcare utilization, employment, poverty, and years since HIV diagnosis. Conclusion: Mental illness and substance use are highly prevalent among adults living with HIV in Texas, and are associated with poor health outcomes. The risk screening tool developed from our study can support efficient care coordination to improve health outcomes for people living with HIV and mental illness or substance use disorders in Texas. Our study findings support the need to prioritize integrated HIV/ mental illness and substance use disorders care in Texas