title: Effects of screening errors and differential mortality on the estimation of the incidence of dementia in the Canadian Study of Health and Aging.
abstract: The Canadian Study of Health and Aging produced an estimate of the incidence of dementia among elderly Canadians by following up, after 5 years, the undemented found in an initial prevalence survey. Initial and follow-up estimates could be biased by false-negative error in the screening tool used for subjects living in the community, and by erroneous classification of subjects who died in the interim. Here, we use a deterministic model to quantify those possible biases. We conclude that, using the estimates of the errors from control samples, the incidence among community subjects would be overestimated by 15%, and the incidence among the institutional subjects would be underestimated by 37%. The overall incidence would be underestimated by 14%. Most of the bias can be attributed to inaccuracies in the classification of deaths.
authors.affiliation: Canadian Study of Health and Aging, University of Ottawa, Ontario, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Hill
authors.forename: I
authors.initials: I
authors.lastname: MacNeill
authors.forename: R
authors.initials: R
authors.lastname: Aylesworth
authors.forename: I
authors.initials: I
authors.lastname: McDowell
authors.forename: W
authors.initials: W
authors.lastname: Forbes
authors.forename: J
authors.initials: J
authors.lastname: Kozak
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015982:Bias; D002170:Canada / Q000453:epidemiology; D002423:Cause of Death; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003625:Data Collection / Q000706:statistics & numerical data; D003704:Dementia / Q000145:classification / Q000401:mortality*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*