Promotie R.W. Maina MSc

In Lower-and-Middle-Income Countries (LMICs) there is a clear need for neurocognitive tools to evaluate children predisposed to cognitive impairment due to conditions such as HIV (Human Immunodeficiency Virus) and stunting (slow growth of height-for-age compared to the general population). Evaluating cognitive impairment, especially in children with HIV and stunting, may help in early diagnosis and treatment to reduce the risk of underperforming in school, dropping out, and the long-term risk effects of reduced income and increased poverty. Cultural aspects play a role in cognitive performance and may contribute to biased performance if the measurement tools are utilized in settings where they were not developed and /or validated. 

The general goals of this research were to review the tools used to evaluate the mental abilities/cognition of lower school students and to adapt and validate the Computerized Battery for Neuropsychological Evaluation of Children (BENCI) in a cohort of Kenyan children living with HIV and those living without HIV. Moreover, we used the BENCI to evaluate the role of stunting in neuropsychological outcomes such as thinking, attention, reasoning and remembering among 6 – 12-year-olds living with HIV. 

Results
In our review of the tools, we found evidence of shortcomings in outcomes measured, psychometric properties evaluated and evidence of development and adaptation. Studies were confined to certain geographical settings, mostly high-income countries and there was a scarcity of adequately adapted, validated, and standardized tools for Sub-Saharan Africa. We concluded that there was a need to conduct subsequent studies to enable valid neuropsychological assessments that monitor development and inform future interventions. 

We, therefore, adapted and validated the BENCI; a preferred tool because it covers the main relevant outcomes of cognition. Successful translation, piloting and testing of psychometric properties resulted in a tool with good reliability or consistent results for most subtests. BENCI also showed that it could measure the same abilities as the few available tools for memory, reasoning, and inhibition. An analytic procedure that shows us how well the outcomes fit constructs such as reasoning, flexibility, verbal memory, and fluency showed that the outcomes fit well and we can reliably compare the constructs outcomes between HIV-positive and HIV-negative groups and also the mean difference for most of the BENCI subtests between the two HIV groups with caution for the language comprehension and short memory subtests. In summary, even though some subtests could be improved in future work, we found the adapted English version of the BENCI to be a valid and reliable neurocognitive tool for use among Kenyan children. Moreover, further research on the potential impact of HIV and stunting on cognitive performance on the BENCI showed that HIV directly impacted stunting and all cognitive outcomes, while stunting was found to (partially) mediate the effects of HIV on reasoning, verbal memory, and fluency. We observed that children with a double burden of HIV and stunting have poorer cognitive performance compared to those with either HIV only or stunting only. 

In settings with a shortage of adequately standardized and robustly validated tools that measure cognitive ability, we can objectively measure disparities in cognition by aligning and validating tools to cultural context. This enables us to know the true burden of impairment and the associated risk factors.