Neurocognitive Assessment

All participants completed a comprehensive and standardized neurocognitive assessment across seven neurocognitive domains commonly impacted by HIV^1,51. Test scores were adjusted for known demographic influences (i.e., age, education, and race/ethnicity) on neurocognitive performance^52–54. Deficit scores that give differential weight to impaired over normal performance were calculated for each domain and averaged to derive a global deficit score (GDS) ranging from 0 (normal) to 5 (severe). Consistent with prior studies, neurocognitive status was classified as impaired (NCI) vs. unimpaired using a validated cut-point of GDS ≥ 0.5^51,55 The GDS is easier to compute, more clearly operationalized (e.g., Frascati criteria do not specify how to apply a 1 SD cutoff to define “impairment” of ability domains with variable numbers of measures) and a more conservative approach to classifying NCI as compared to the clinical ratings algorithm used in Frascati criteria for HIV-associated Neurocognitive Disorders; however, an individual classified as impaired via GDS ≥ 0.5 is essentially guaranteed to meet the NCI aspect of Frascati criteria⁵⁵.