Neuropsychological function in asymptomatic HIV-1 infection: methodological issues

Abstract

There have been conflicting reports as to whether significant neuropsychological deterioration occurs in asymptomatic HIV-1 infection. Comparisons among studies have been hindered by substantial variations in sample size, statistical methods, definitions of neuropsychological abnormality, and attention to potential confounding factors. In this study, the neuropsychological performance of 44 subjects with asymptomatic HIV-1 infection and 41 seronegative (SN) controls was compared using analysis of variance models. Rates of abnormality were also determined using commonly employed impairment criteria. The seropositive (SP) subjects performed comparably to SN controls once differences in full scale IQ were taken into account. Rates of abnormality for HIV-1 SP subjects were estimated at 10%, 17.5%, and 67.5% by three different criteria, and were not significantly different from the rates of the control group. The findings indicated that both premorbid characteristics, and the validity and biases of definitions of impairment should be examined and incorporated into the interpretation of study findings.