Social Determinants of Health and Cross-Sectional Cognitive Intra-Individual Variability in Adults from the Deep...

Cognitive intra-individual variability (IIV) is a sensitive marker of neuropathology and is increased in people with HIV (PWH). In a sample of PWH from the United States Deep South, we examined the relationship of cognitive IIV with cognitive impairment and social determinants of health (SDoH). This secondary analysis included 131 PWH from a larger cognitive training protocol. Our primary outcome measure was the coefficient of variation (CoV). We also included the individual standard deviation (iSD), with both calculated from demographically adjusted T-scores and unadjusted sample-based scores. Mixed-effects models investigated the relationship between IIV and cognitive impairment severity (i.e., Global Rating Score), SDoH, and clinical variables. Bivariate correlations were used to further explore these relationships. Greater cognitive IIV was associated with greater cognitive impairment in PWH, when accounting for demographic factors. When IIV is calculated from the sample, then IIV is no longer associated with cognitive impairment, but is associated with race (>IIV in Black and African American participants). Demographically adjusted IIV is associated with global cognition, Wide Range Achievement Test-Fourth Edition reading score, and viral load (iSD only). No correlations were significant when using the unadjusted sample-based IIV metrics. In PWH from the Deep South, greater cognitive variability is seen in those with greater cognitive impairment, in Black participants, and in those with lower reading scores. Further research on the psychometric properties of IIV in HIV and other populations is needed, as results varied depending on the normative adjustments.