Incidence and outcomes of diabetes mellitus in elderly people: report from the Canadian Study of Health and Aging.
BACKGROUND
The epidemiology of diabetes in elderly people is not well understood. The purpose of this study was to estimate the incidence of diabetes mellitus among elderly people in Canada and the relative risks of death and admission to an institution among elderly diabetic patients.


METHODS
The study was a secondary analysis of data for a community-dwelling sample from the Canadian Study of Health and Aging, a nationwide representative cohort study of 9008 elderly people (65 years of age or older at baseline) in Canada. Diabetes was identified primarily by self-reporting, and a clinician's diagnosis and the presence of treatments for diabetes were used to identify diabetic patients who did not report that they had the condition.


RESULTS
The reliability of self-reported diabetes (the kappa statistic) was 0.85. The estimated annual incidence of diabetes was 8.6 cases per thousand for elderly Canadians. Incidence decreased with age, from 9.5 for subjects 65-74 years of age, to 7.9 for those 75-84 years of age and then to 3.1 for those 85 years of age and older. Diabetes was associated with death (relative risk 1.87, 95% confidence interval 1.59-2.19) and admission to an institution (relative risk 1.58, 95% confidence interval 1.28-1.94).


CONCLUSIONS
Diabetes mellitus is common among elderly people, but the incidence declines among the very old.
Rockwood
K
K
Division of Geriatric Medicine, Dalhousie University, Halifax, NS. rockwood@is.dal.ca
Awalt
E
E
MacKnight
C
C
McDowell
I
I
D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000401:mortality*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D010343:Patient Admission / Q000706:statistics & numerical data*; D012306:Risk; D015996:Survival Rate