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O2–13–02: Assessing long‐term postoperative cognitive decline using conventional and quasi‐experimental approaches: A Monte Carlo simulation study
Author(s) -
Llewellyn David,
Lang Iain,
Langa Kenneth,
Henley William
Publication year - 2013
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2013.04.208
Subject(s) - coronary artery bypass surgery , cognition , monte carlo method , cognitive decline , medicine , ordinary least squares , cardiology , statistics , mathematics , artery , psychiatry , dementia , disease
where age at dementia diagnosis or age at censoring (31st December 2010) was the dependent variable and age of retirement was the independent variable. Hazard ratios were computed adjusting for gender, marital status, occupational category, type of retirement, pension amount, diagnosis of hypertension, diabetes. Sensitivity analyses to assess potential reverse causation and differential cohort or temporal diagnosis biases were undertaken. Results: Among the 429,803 retired self-employed workers alive on December 31st 2010, prevalence of dementia was 2.65%.Workers had been retired on average for more than 12 years. Multivariable analyses showed that the hazard ratio (HR) of dementia was 0.968 (95% Confidence Interval1⁄4 [0.962-0.973]) per each extra year of age at retirement. After excluding workers who had dementia diagnosed within the 5 years following retirement, the results remained unchanged and highly significant (p<0.0001). Results were also similar in further analyses stratified by age categories or year of dementia diagnosis. Conclusions: Professional activity may be an important determinant of mental exercise and social integration. Our data show strong evidence of a significant decrease in the risk of developing dementia associated with older age at retirement, in line with the "use it or lose it" hypothesis. This health perspective should be taken into consideration when the age of cessation of professional activity is discussed. Our results thus highlight the importance of maintaining high levels of cognitive and social stimulation throughout work and retiree life and emphasize the need for interventions and policies to help older individuals achieve such cognitive and social engagement.