Education, wealth, and survival after dementia diagnosis

Abstract

AbstractBackgroundThe relationship between socio‐economic status (SES) and length of life after dementia diagnosis may vary by specific aspects of SES. Education and wealth, two widely used measures of SES, may extend life expectancy via greater efficiency of health investment and better access to care. However, according to the cognitive reserve hypothesis, education protects against dementia pathology and thus when dementia symptoms manifest, individuals with higher education have more advanced atrophy, likely shortening their post‐dementia life expectancy. This paper examined education and wealth disparities in 1) timing of dementia diagnosis, 2) length of life after diagnosis, and 3) use of healthcare after diagnosis as a potential mechanism through which education and wealth differentially influence survival.MethodData was extracted from the Health and Retirement Study (HRS) linked to Medicare claims. From claims we identified 2,377 individuals with incident dementia diagnosis between 2000 and 2016 and followed them for up to 18 years. Using Cox proportional hazard models, we estimated relationships between education, household wealth, and mortality, adjusting for demographics, comorbidity, function, and cognition at the time of dementia diagnosis. To test whether SES disparities were driven by healthcare utilization, we ran linear regressions on the number of emergency room (ER) visits, inpatient admissions, and office visits after diagnosis with the same set of predictors.ResultIndividuals with higher education and wealth exhibited less functional and cognitive impairment at dementia diagnosis. The protective effect of higher education on mortality was absorbed by controlling for wealth. In the fully adjusted model, ranking in the top quartile of wealth was associated with a 17% reduction in mortality risk (HR = 0.83, 95% CI: 0.72‐0.96), relative to the bottom quartile. Wealth was not associated with ER visits, hospitalization, or office visits.ConclusionMore intact function and cognition at incident diagnosis did not confer longer survival for the highly educated. In contrast, the most affluent experienced a lower mortality risk, which was unrelated to healthcare utilization. While more research is warranted to understand pathways, these disparities inform opportunities for achieving health equities among persons living with dementia, by targeting at those with limited financial resources.