Predictors of Art Adherence among HIV-infected Persons Receiving Medical Care in Houston, Texas

Background: Although antiretroviral therapy (ART) has transformed HIV infection into a manageable chronic condition, optimal adherence is crucial to achieving viral suppression and positive health outcomes in people living with HIV (PLWH). However, the adherence rate across time following ART medication initiation among PLWH are inconsistent in the literature. This study examined the sociodemographic, behavioral, and clinical characteristics associated with 100% ART adherence after HIV diagnosis among PLWH receiving medical care in Houston/Harris County, Texas. ^ Methods: Data used for this study (n = 1,073; weighted n = 10,274) were obtained from the Houston Medical Monitoring Project survey conducted among PLWH in Houston/Harris County between 2009 and 2014. The combined ART adherence was defined as adherence to all, some, and none in relation to medication dose, schedule, and instruction. The number of years since initial HIV diagnosis was classified as \u3c5, 5-10 and \u3e10 years. Other covariables considered in the analyses were sociodemographic, behavioral, and clinical characteristics obtained during the interview process and the medical record abstraction. The Rao-Scott chi-square test and multivariable logistic models were used to determine the predictors of the combined ART adherence to all medication dose, schedule, and instruction. ^ Results: Overall, 54.4% of the PLWH were adherent to all medication dose, schedule, and instruction, with significant (p = 0.022) variation noted across years since HIV diagnosis. PLWH who were diagnosed with HIV less than 5 and between 5 and 10 years were approximately two times (aOR = 1.71, 95% CI = 1.13 – 2.57; aOR = 1.69%, 95% CI = 1.10 – 2.59; respectively) more likely to be adherent to all medication requirements compared to those diagnosed for more than 10 years. Among PLWH who were diagnosed with HIV for less than 5 years, significant predictors of all adherence were incarceration (aOR = 4.51, 95% CI = 1.27 – 16.05), confidence taking all or most medication as directed (aOR = 5.28, 95% CI = 1.29 – 21.67), and prior HPV vaccination (aOR = 3.23, 95% CI = 1.03 – 10.08). For PLWH who were diagnosed between 5 and 10 years, significant predictors were depression (absence of vs. major depression: aOR = 10.30, 95% CI = 2.63 – 40.37; other types of vs. major depression: aOR = 6.32, 95% CI = 1.63 – 26.68); belief that HIV will become resistant to medication if the patients did not take medication as directed (aOR 7.34, 95% CI = 1.29 – 41.83); and history of medical care treatment (aOR = 0.18, 95% CI = 0.04 – 0.82). For PLWH who were diagnosed for more than 10 years, significant predictors of all adherence were heavy drinking (aOR = 3.32, 95% CI = 1.01 – 10.00) and confidence taking all or most medication as directed (aOR = 8.88, 95% CI = 3.54 – 22.28). ^ Conclusion: Predictors of all ART adherence varied significantly by years since HIV diagnosis. Intervention programs to enhance optimal ART adherence should consider the predictors identified in this study. These supporting programs could lead to improved long-term adherence which is critical to the maintenance of viral suppression and positive health outcomes among the population.