Higher education delays and shortens cognitive impairment. A multistate life table analysis of the US Health and Retirement Study

Abstract

Improved health may extend or shorten the duration of cognitive impairment by postponing incidence or death. We assess the duration of cognitive impairment in the US Health and Retirement Study (1992–2004) by self reported BMI, smoking and levels of education in men and women and three ethnic groups. We define multistate life tables by the transition rates to cognitive impairment, recovery and death and estimate Cox proportional hazard ratios for the studied determinants. 95% confidence intervals are obtained by bootstrapping. 55 year old white men and women expect to live 25.4 and 30.0 years, of which 1.7 [95% confidence intervals 1.5; 1.9] years and 2.7 [2.4; 2.9] years with cognitive impairment. Both black men and women live 3.7 [2.9; 4.5] years longer with cognitive impairment than whites, Hispanic men and women 3.2 [1.9; 4.6] and 5.8 [4.2; 7.5] years. BMI makes no difference. Smoking decreases the duration of cognitive impairment with 0.8 [0.4; 1.3] years by high mortality. Highly educated men and women live longer, but 1.6 years [1.1; 2.2] and 1.9 years [1.6; 2.6] shorter with cognitive impairment than lowly educated men and women. The effect of education is more pronounced among ethnic minorities. Higher life expectancy goes together with a longer period of cognitive impairment, but not for higher levels of education: that extends life in good cognitive health but shortens the period of cognitive impairment. The increased duration of cognitive impairment in minority ethnic groups needs further study, also in Europe.

Investigating healthy life expectancy using a multi-state model in the presence of missing data and misclassification

“…The estimated effect of education implies that more education delays the onset of cognitive impairment but shortens the stay in the impaired state. This agrees with the results presented in Reuser, Willekens, and Bonneux (2011). Men are less likely to move to the impaired state than women but have a higher mortality rate.…”

Demographic Epidemiologic Projections of Long-Term Care Needs in Selected European Countries: Germany, Spain, the Netherlands and Poland

“…This might not be true. Indeed, for dementia (a most important cause of disability), we can observe lower mortality at early stages but increased mortality at later clinical stages among more highly educated people -a consequence of more successful adaptation to cognitive decline by highly educated persons (Reuser, Willekens and Bonneux, 2011). More highly educated people can stave off clinical dementia until they reach advanced stages of severe disease and poor prognosis.…”

A Budget Proposal for China’s Public Long-Term Care Policy

“…It is possible that with further education level increase, the frailty of elders will decrease in time (Santos-Eggimann, Cuénoud, Spagnoli & Junod, 2009;Reuser, Willekens & Bonneux, 2011).…”