Effect of age and level of education on neurocognitive impairment in HIV positive Zambian adults.

OBJECTIVE: Older age and lower education levels are known to be associated with worse neurocognitive (NC) performance in healthy adults, and individuals with HIV infection may experience accelerated brain/cognition aging. However, higher education may possibly protect against HIV-associated neurocognitive disorders (HAND). The aim of the current cross-sectional study was to assess the effect of age and education in an HIV-1 clade C infected adult population in urban Zambia. METHOD: Demographically corrected Zambian norms on a neuropsychological (NP) test battery were used to correct for normal age and education effects. The study assessed 286 HIV positive (+) males (37.1%) and females (62.9%) with a mean age of 41.35 (SD = 8.56) and mean years of education = 10.16 (SD = 2.18). A comprehensive NP test battery was used to assess cognitive domains frequently affected by HIV: attention/working memory, learning/and delayed recall, executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills. RESULTS: In younger HIV+ Zambians, higher education evidenced protective effects against NC impairments overall, and for the specific domains of executive functions, learning and speed of information processing. Impairment scores did not support accelerated overall brain aging although the restricted age range and relative youth of our total sample may have precluded detection of such tendencies. CONCLUSIONS: The present study raises the need to investigate factors that could be implicated in the poor neurocognitive performance among the younger, less educated HIV+ individuals in Zambia. (PsycINFO Database Record

Use of Western Neuropsychological Test Battery in Detecting HIV-Associated Neurocognitive Disorders (HAND) in Zambia.

This is a study of neuroAIDS in sub-Saharan Africa, involving 266 Zambian adults infected with the human immunodeficiency virus (HIV), clade C. All HIV+ participants were receiving combination antiretroviral therapy (CART), and were administered a comprehensive neuropsychological (NP) test battery covering seven ability domains that are frequently affected by neuroAIDS. The battery was developed in the U.S. but has been validated in other international settings and has demographically-corrected normative standards based upon 324 healthy Zambian adults. Compared to the healthy Zambian controls, the HIV+ sample performed worse on the NP battery with a medium effect size (Cohen's d = 0.64). 34.6 % of the HIV+ individuals had global NP impairment and met criteria for HIV associated neurocognitive disorder (HAND). The results indicate that the Western-developed NP test battery is appropriate for use in Zambia and can serve as a viable HIV and AIDS management tool.

HIV- and AIDS-associated neurocognitive functioning in Zambia - a perspective based on differences between the genders.

Human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) are frequently associated with neurocognitive impairment (NCI). However, few studies have examined the interrelationship between gender and NCI in the HIV and AIDS population. This cross-sectional study examined the neurocognitive (NC) functioning of HIV-infected male and female adults from urban Zambia. The participants included 266 HIV seropositive (HIV+) adults (males [n=107] and females [n=159]). Participants completed NC assessment by means of a comprehensive test battery using normative data from 324 HIV-seronegative (HIV-) controls. The norms corrected for effects of age, education, and gender in the general population, and the test battery measures domains of attention/working memory (learning and delayed recall), executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills. An overall comparison of the HIV+ male and female participants yielded no statistically significant differences. Analysis of covariance results controlling for disease characteristics showed that HIV+ female participants had worse delayed recall scores than males, F(1,117) =9.70, P=0.002, partial η(2)=0.077. The females also evidenced a trend toward greater impairment on learning efficiency (P=0.015). The findings suggest that there are gender-related differences in NCI after controlling for disease characteristics. It was observed that although the HIV+ females enjoyed better health compared to their HIV+ male counterparts, they still had worse performance on the neuropsychological tests. This implies that HIV may have more NC consequences for Zambian females than males.

Do neuropsychological test norms from African Americans in the United States generalize to a Zambian population?

Healthy Zambian adults (N = 324) were evaluated to determine to what degree a Western neuropsychological (NP) test battery, with African American norms adjusted for age, gender, and education could be used in healthy Zambians, including 157 men (48.46%) and 167 women (51.54%) with an average age of 38.48 (SD = 12.80) years and an average education level of 11.02 (SD = 2.58) years. The NP battery included tests of attention/working memory, executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills. The Zambian Achievement Test (ZAT) and the U.S. Wide Range Achievement Test-4 (WRAT-4) reading subtest also were administered to assess literacy and quality of education. Similar to findings in Western countries, the Zambian results show substantial age and education effects on most tests and smaller, less consistent effects of gender. Beyond the basic demographic effects, urban/rural background had small effects on some cognitive variables, and the ZAT (but not WRAT-4) reading level was a robust predictor of performance on many NP tests, even when other background characteristics were controlled. Women in the United States tend to outperform men on tests of processing speed and episodic memory. However, Zambian women showed modest but statistically significant disadvantages versus their male counterparts. The results show that tests developed in the United States may be used in Zambia. Nevertheless, development and use of local cultural norms remains very important and is a must. New demographically corrected norms were developed for the cohort that was examined.