The Veterans Aging Cohort Study (VACS) Index is a composite marker of multisystem injury among HIV-infected persons. We aimed to examine its cross-sectional association with functional outcomes, after considering neurocognitive impairment (NCI) and other well-established correlates of everyday functioning among HIV-infected persons. Participants included 670 HIV-infected adults (ages 18-76; 88% male; 63% non-Hispanic White; median current CD4 = 404 cells/mm3; 67% on antiretroviral therapy; AIDS = 63%) enrolled in observational studies at the University of California San Diego HIV Neurobehavioral Research Program. Functional outcomes were assessed via self-report measures of declines in activities of daily living, perceived cognitive symptoms in daily life, and employment status. NCI was assessed via a comprehensive neurocognitive test battery and defined based on established methods. Covariates examined included demographics, HIV disease characteristics not included in the VACS Index, and psychiatric comorbidities. The VACS Index was computed via standard methods and categorized based on its distribution. Results from multivariable regression models showed that both higher VACS Index scores (indicative of worse health) and the presence of NCI were independently associated with declines in activities of daily living, increased cognitive symptoms in daily life, and unemployment. These independent effects remained after adjusting for significant covariates. In conclusion, the VACS Index may be a useful tool for identifying HIV-infected patients at high risk for everyday functioning problems. Considering factors such as NCI, historical HIV disease characteristics, and current mood might be particularly important to enhance the predictive power of the VACS Index for functional status among HIV-infected persons.
Keywords: AIDS; Activities of daily living; Biomarkers; Comorbidity; Employment status; Neurobehavioral manifestations.