Non-verbal ability as an estimator of premorbid intelligence: Does it remain stable among ethnically diverse HIV+ adults?
The estimation of premorbid intellectual functioning is an integral step in establishing a patient’s baseline performance prior to brain injury or disease in order to determine the presence or degree of impairment. While measures assessing reading level are commonly utilized, evidence suggests that nonverbal measures like the General Ability Measure for Adults (GAMA) are useful when disparities in education quality render reading-based measures an inadequate proxy for premorbid functioning. However, the long-term stability of this nonverbal measure has not been established. This is important in the context of HIV, as it has become more of a chronic disease in which individuals are living longer and display great fluctuation in disease characteristics (i.e., medical and neurocognitive status) over time. Therefore, it is expected that an estimate of premorbid intellectual functioning remains stable across all groups, despite fluctuations in these characteristics or lengthy time intervals. This MA thesis project examined the long-term test-retest reliability of this measure in an ethnically diverse sample of HIV+ individuals. Participants (N=79) completed a comprehensive neuropsychological battery, including the GAMA, on two study visits. Intraclass correlation coefficients (ICCs) were computed using GAMA scores from the first and second test administrations to determine the test-retest reliability of the overall group and across subgroups based on demographic characteristics (i.e., race/ethnicity, years of education), test-retest intervals, and changes in medical (i.e., CD4, HIV RNA viral load) and neurocognitive characteristics. Results suggest that the test-retest reliability of the GAMA was high (ρ = .81, p < .001) for the overall group, and remained moderate to high across all demographic, medical and clinical subgroups (all ρ’s > .58, p < .05), with the exception of Hispanic/Latino participants (ρ = .51, p > .05). Overall, results from this study support the utilization of the GAMA as a stable nonverbal estimate of premorbid intellectual functioning for most groups except Hispanic/Latino populations, implying that clinicians and researchers must exercise caution when assessing these individuals. The present study has important clinical implications about the importance of accounting for culture, race and ethnicity when choosing appropriate methods of estimating premorbid intellectual functioning.
Olsen, James Patrick, "Non-verbal ability as an estimator of premorbid intelligence: Does it remain stable among ethnically diverse HIV+ adults?" (2016). ETD Collection for Fordham University. AAI10190763.