Reliability, minimum detectable change and sociodemographic biases of selected neuropsychological tests among people living with HIV in south-eastern Nigeria

Abstract

Verification of the psychometric properties of neuropsychological (NP) tests in each society of people living with HIV (PLWHIV) will facilitate accurate classification of HIV-associated neurocognitive disorder. This study aimed to determine the reliability, minimum detectable change (MDC) and sociodemographic biases of selected NP tests among PLWHIV. The study took place at the HIV clinic of the University of Nigeria Teaching Hospital, Enugu. A total of 60 PLWHIV were randomly recruited into two groups of 30 each. The first group was evaluated by two independent examiners (inter-rater) and the other by a single rater (intra-rater). The NP tests utilised included the Hopkins Verbal Learning Test-Revised (HVLT-R), controlled oral word association test (COWAT), Trail Making Test-A (TMT-A) and -B (TMT-B), Digit Span Test-forward (DST-f) and -backward (DST-b). We examined agreement using intra-class correlation (ICC), standard error of measurement and MDC. We verified the influence of sociodemographic variables on test performance using Man–Whitney U-test and Kruskal–Wallis test. The HVLT-R- delay recall (DR), TMT-A, TMT-B and COWAT showed excellent inter-rater reliability with ICC values of 0.83, 0.86, 0.78 and 0.89, respectively. The HVLT-R- verbal learning (VL), DST-f and DST-b showed moderate inter-rater reliability with ICCs of 0.4.99, 0.52 and 0.60, respectively. The HVLT-R-DR, TMT-A, DST-b and COWAT showed excellent intra-rater reliability, with ICCs values of 0.76, 0.80, 0.84 and 0.97, respectively. The TMT-A, DST-f and DST-b were free from sociodemographic bias. The HVLT-R-DR, TMT-A, TMT-B, DST-f, DST-b and COWAT are reliable candidate NP tests for PLWHIV in our setting.