Poverty increases the risk of incident cognitive impairment among older adults: a longitudinal study in China

Objectives: With a longitudinal design, we aimed to investigate the relationship between poverty and the risk of incident cognitive impairment in China. Methods: We used three waves of the Chinese Longitudinal Healthy Longevity Survey (2008-2014). Cognitive impairment was assessed using the Chinese version of the Mini Mental State Examination. Poverty was measured according to the latest national poverty line settled at an annual per-capita income of 2300 yuan (approximately equivalent to 1.25 dollar/day) in 2011 in China. A marginal structural model was utilized to explore the association between poverty and the risk of incident cognitive impairment. The subgroup analyses were also conducted in this study. Results: The cumulative incidence of cognitive impairment over 6 years was 30.69% (1936/6309). Poverty increased 34% risk of incident cognitive impairment in the elderly (odds ratio = 1.34, 95% confidence interval (CI): 1.15-1.56) after controlling behavioral factors and health status covariates. Participants who were male (OR = 1.38, 95% CI: 1.08-1.76), lived in urban areas (OR = 1.55, 95% CI: 1.22-1.98), and were married (OR = 1.72, 95% CI: 1.28-2.32) had higher poverty risks on incident cognitive impairment in subgroup analyses. Conclusions: Our results provide empirical support for the ongoing discussion about how economic hardship impacts of cognitive functioning, and highlight the negative health risks that economically disadvantaged individuals may experience.