Social determinants of health and risk of dementia among older men and women: A 12-year cohort study in Australia

INTRODUCTIONSocial determinants of health (SDH) are recognized as contributing factors to cognitive disorders, but their collective influence on dementia risk remains unclear.METHODSA gender-disaggregated analysis was conducted on 12,896 community-dwelling older Australians (mean +/- SD age: 75.2 +/- 4.3 years; 54% women) without major cognitive impairment upon enrollment. Latent class analysis identified clusters from 72 SDH (70 individual-level and 2 neighborhood-level), while Cox proportional hazards regression estimated dementia risk over 12 years (median: 8.4) follow-up.RESULTSFour clusters were identified: least disadvantaged (Class 1: 31.5% men; 30.6% women), most disadvantaged (Class 2: 20.2% men; 19.4% women), high social support with Class 1 features (Class 3: 22.2% men; 24.1% women), and high social support with Class 2 features (Class 4: 26.1% men; 25.7% women). Compared to Class 1, men (HR: 1.49, 95% CI: 1.12-1.98) and women (HR: 1.56, 95% CI: 1.17-2.07) in Class 2, and women in Class 4 (HR: 1.66, 95% CI: 1.28-2.16) had a higher dementia risk.DISCUSSIONSocioeconomic disadvantage was associated with incident dementia. Despite stronger social support, women's cognitive capacity appeared to be disproportionately impacted by adverse SDH.Highlights Four distinct multidimensional clusters were identified from a wide range of 72 social determinants of health. These clusters were associated with dementia risk differently in men and women. In both men and women, the most socioeconomically disadvantaged group had a higher risk of dementia. Despite stronger interpersonal social support, women had a greater risk of dementia. The addition of known dementia risk factors in cluster analysis did not change the findings, suggesting that social determinants of health independently predict dementia risk.