Browsing by Author "Nele Demeyere"

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    Executive function associated with sexual risk in young South African women: Findings from the HPTN 068 cohort
    (2018-04-02) Molly Rosenberg; Audrey Pettifor; Mihaela Duta; Nele Demeyere; Ryan G. Wagner; Amanda Selin; Catherine MacPhail; Oliver Laeyendecker; James P. Hughes; Alan Stein; Stephen Tollman; Kathleen Kahn
    Purpose Heightened sexual risk in adolescence and young adulthood may be partially explained by deficits in executive functioning, the set of cognitive processes used to make reasoned decisions. However, the association between executive function and sexual risk is understudied among adolescent girls and young women, particularly in low- and middle-income countries. Methods In a cohort of 853 young women age 18–25 in rural Mpumalanga province, South Africa, we evaluated executive function with three non-verbal cognitive tests: I. a rule-finding test, II. a trail-making test, and III. a figure drawing test. Using log-binomial regression models, we estimated the association between lower executive function test scores and indicators of sexual risk (unprotected sex acts, concurrent partnerships, transactional sex, and recent HSV-2 infection). Results In general, young women with lower executive function scores reported higher frequencies of sexual risk outcomes, though associations tended to be small with wide confidence intervals. Testing in the lowest quintile of Test I was associated with more unprotected sex [aPR (95% CI): 1.4 (1.0, 1.8)]. Testing in the lowest quintile of Test II was associated with more concurrent relationships and transactional sex [aPR (95% CI): 1.6 (1.1, 2.5) and 1.7 (1.3, 2.4), respectively], and testing in the lowest four quintiles of Test III was associated with more concurrent relationships [aPR (95% CI): 1.7 (1.0, 2.7)]. Conclusions These results demonstrate an association between low executive function and sexual risk in South African young women. Future work should seek to understand the nature of this association and whether there is promise in developing interventions to enhance executive function to reduce sexual risk.
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    Validation of Oxford Cognitive Screen: Executive Function (OCS-EF), a tablet-based executive function assessment tool amongst adolescent females in rural South Africa
    (2021) Kirsten Rowe; Mihaela Duta; Nele Demeyere; Ryan G. Wagner; Audrey Pettifor; Kathleen Kahn; Stephen Tollman; Gaia Scerif; Alan Stein
    Short, reliable, easily administered executive function (EF) assessment tools are needed to measure EF in low- and middle-income countries, particularly in sub-Saharan Africa given the prevalence of human immunodeficiency virus (HIV)-associated neurocognitive disorder. We administered Oxford Cognitive Screen—Executive Function (OCS-EF) to 932 rural South African females (mean age 19.7 years). OCS-EF includes seven tasks: two hot inhibition tasks (a modified Iowa Gambling Task, emotional go/no-go) and five cool EF tasks, two switching tasks (visuospatial rule-finding, geometric trails) and three working memory tasks (digit recall, selection and figure drawing). We performed confirmatory factor analysis testing whether a three-factor, two-factor hot-cool, two-factor working memory and inhibition/switching, or one-factor EF model fitted the data better. The three-factor (switching, inhibition and working memory) model had the best local and global fit (χ2 (11) 24.21, p = 0.012; RMSEA 0.036; CFI 0.920; CD 0.617). We demonstrated the feasibility of OCS-EF administration by trained laypeople, the tripartite structure of EF amongst adolescent females and the factorial validity of OCS-EF in this population and context. OCS-EF tablet-based cognitive assessment tool can be administered by trained laypeople and is a valid tool for assessing cognition at scale amongst adolescents in rural South Africa and similar environments.