Socio-Economic Status and Neuropsychological test performance in Zambia

Introduction :To understand the brain-behaviour relationship, systematic neuropsychological assessments are undertaken using a validated battery of tests to ascertain one‘s brain integrity and levels of cognitive functioning (Hestad et al., 1998; Kaplan et al., 2001). These tests are however affected by background factors such as age, education, socio-economic status, ethnicity and so on (Strauss et al., 2006). This study was undertaken with the overall aim of investigating the influence of socio-economic status (SES) on people‘s neuropsychological test performance on the Zambia Neuropsychological test battery.
Specifically, the objectives were to: (1) establish the level to which each of the four SES indices (education, occupation, income, and residence) predict neuropsychological test performance; (2) determine which tests in the Zambia neuropsychological test battery show the most relationship with SES; and (3) establish if there is a significant difference in mean test scores between high and low SES participants on the Zambia neuropsychological test battery.
Design:The study was a quantitative one involving 324 participants aged between 18 to 65 years with 5 and more years of education from both rural and urban places in Zambia. After screening, the participants were subjected to a series of neuropsychological tests in the Zambian neuropsychological test battery.
Results:In this study, of the four SES indices, occupation predicted 27% of neuropsychological test performance followed by education (19%). The predictive ability of income and residence were not statistically significant (p>.05). Further, SES had a strongest positive correlation with language fluency tests (r=.46) followed by information processing tests (r=.32), memory tests (r=.24), executive functioning tests (r=.23), motor test (r=.20), and visual episodic memory tests (r=.14). On the overall neuropsychological test performance, high SES participants performed better (mean score=11.11) than their low SES counterparts (mean score= 9.94).Conclusion:In conclusion, it cannot go without emphasising that the clients‘ SES should be considered when interpreting test results especially on language fluency and information processing speed tests that are more influenced by SES. Further, standardised norms referenced scores for low and high SES individuals should be used to avoid overdiagnosing or underdiagnosing clients.Design
The study was a quantitative one involving 324 participants aged between 18 to 65 years with 5 and more years of education from both rural and urban places in Zambia. After screening, the participants were subjected to a series of neuropsychological tests in the Zambian neuropsychological test battery.Results:In this study, of the four SES indices, occupation predicted 27% of neuropsychological test performance followed by education (19%). The predictive ability of income and residence were not statistically significant (p>.05). Further, SES had a strongest positive correlation with language fluency tests (r=.46) followed by information processing tests (r=.32), memory tests (r=.24), executive functioning tests (r=.23), motor test (r=.20), and visual episodic memory tests (r=.14). On the overall neuropsychological test performance, high SES participants performed better (mean score=11.11) than their low SES counterparts (mean score= 9.94).Conclusion:In conclusion, it cannot go without emphasising that the clients‘ SES should be considered when interpreting test results especially on language fluency and information processing speed tests that are more influenced by SES. Further, standardised norms referenced scores for low and high SES individuals should be used to avoid overdiagnosing or underdiagnosing clients.