Subjective social position and cognitive function in a longitudinal cohort of older, rural South African adults, 2014–2019. Issue 4 (23rd September 2021)

• Record Type: Journal Article
• Authors: Kobayashi, Lindsay C; Morris, Emily P; Harling, Guy; Farrell, Meagan T; Kabeto, Mohammed U; Wagner, Ryan G; Berkman, Lisa F
• Is Part Of: Journal of epidemiology and community health. Volume 76:Issue 4(2022)
• Page Start: 385
• Page End: 390
• Publication Date: 2021-09-23
• Subjects: aging -- cohort studies -- cognition -- international health -- social epidemiology; Public health -- Periodicals; Epidemiology -- Periodicals; 614.4
• DOI: 10.1136/jech-2021-217059
• Languages: English
• ISSNs: 0143-005X

Abstract

Abstract : Background: The relationship between subjective social position (SSP) and cognitive ageing unclear, especially in low-income settings. We aimed to investigate the relationship between SSP and cognitive function over time among older adults in rural South Africa. Methods: Data were from 3771 adults aged ≥40 in the population-representative 'Health and Ageing in Africa: A Longitudinal Study of an INDEPTH Community in South Africa' from 2014/2015 (baseline) to 2018/2019 (follow-up). SSP was assessed at baseline with the 10-rung MacArthur Network social position ladder. Outcomes were composite orientation and episodic memory scores at baseline and follow-up (range: 0–24). Mortality- and attrition-weighted linear regression estimated the associations between baseline SSP with cognitive scores at each of the baseline and follow-up. Models were adjusted for age, age 2, sex, country of birth, father's occupation, education, employment, household assets, literacy, marital status and health-related covariates. Results: SSP responses ranged from 0 (bottom ladder rung/lowest social position) to 10 (top ladder rung/highest social position), with a mean of 6.6 (SD: 2.3). SSP was positively associated with baseline cognitive score (adjusted β=0.198 points per ladder rung increase; 95% CI 0.145 to 0.253) and follow-up cognitive score (adjusted β=0.078 points per ladder rung increase; 95% CI 0.021 to 0.136). Conclusion: Independent of objective socioeconomic position measures, SSP is associated with orientation and episodic memory scores over two time points approximately 3 years apart among older rural South Africans. Future research is needed to establish the causality of the observed relationships, whether they persist over longer follow-up periods and their consistency in other populations.