Normative scores for select neuropsychological battery tests for the detection of HIV-associated neurocognitive disorder amongst Nigerians.

Background: The study aimed to derive socio-demographic-corrected norms for selecting neuropsychological (NP) battery tests for people living with HIV (PLWHIV) in Nigeria. This cross-sectional study was conducted amongst patients who attended the general outpatient clinic and junior staff of the University of Nigeria Teaching Hospital (UNTH), Ituku-Ozalla.

Aims and objectives: To determine the normative scores for select neuropsychological battery test for the detection of neurocognitive disorder amongst Nigerians PLWHIV. A sample of 92 individuals received voluntary HIV testing.

Methods: Eligibility criteria were being HIV negative, aged 18-64 years and formal education. We undertook a brief neuromedical examination to identify putative exclusion criteria. We sampled four NP tests covering seven cognitive domains and the motor speed component of the International HIV Dementia Scale (IHDS-MS). We presented the normative scores using statistics of mean, median, standard deviation (SD), kurtosis and skewness.

Results: All the participants were Nigerians aged 18-64 years. Most (74.1%) of the participants were females. The mean and median ages of the participants were 42.6 ± 11.42 years and 44 years, respectively. The effect of gender on NP performance was limited to the digit span test (DST)-forwards, while education affected all expect IHDS-MS and DST-backwards. The cut-off scores for defining mild and severe impairment varied (moving from 1SD to 2SD) for all cognitive domains except for IHDS-MS and DST.

Conclusions: With these preliminary normative scores, it will be easier to identify and classify the severity of neurocognitive impairment amongst PLWHIV in Nigeria, thus facilitating the goal of keeping HIV-associated dementia to a minimum. The lack of variability in the IHDS-MS and DST is unfavourable.