Reading Ability as an Estimator of Premorbid Intelligence: Does It Remain Stable Among Ethnically Diverse HIV+ Adults?

Abstract

The Wide Range Achievement Test, 3rd edition, Reading Recognition subtest (WRAT-3 RR) is an established measure of premorbid ability. Furthermore, its long-term reliability is not well documented, particularly in diverse populations with CNS-relevant disease. Objective: We examined test–retest reliability of the WRAT-3 RR over time in an HIV+ sample of predominantly racial/ethnic minority adults. Method: Participants (N = 88) completed a comprehensive neuropsychological battery, including the WRAT-3 RR, on at least two separate study visits. Intraclass correlation coefficients (ICCs) were computed using scores from baseline and follow-up assessments to determine the test–retest reliability of the WRAT-3 RR across racial/ethnic groups and changes in medical (immunological) and clinical (neurocognitive) factors. Additionally, Fisher’s Z tests were used to determine the significance of the differences between ICCs. Results: The average test–retest interval was 58.7 months (SD = 36.4). The overall WRAT-3 RR test–retest reliability was high (r = .97, p < .001) and remained robust across all demographic, medical, and clinical variables (all r’s > .92). ICCs did not differ significantly between the subgroups tested (all Fisher’s Z p’s > .05). Conclusions: Overall, this study supports the appropriateness of word-reading tests, such as the WRAT-3 RR, for use as stable premorbid IQ estimates among ethnically diverse groups. Moreover, this study supports the reliability of this measure in the context of change in health and neurocognitive status and in lengthy inter-test intervals. These findings offer strong rationale for reading as a “hold” test, even in the presence of a chronic, variable disease such as HIV.