Dementia and Alzheimer Disease Incidence

Abstract

THE BURDEN of dementia on the public health is increasing rapidly as our population ages. Dementia occurs more frequently in the older age groups. Prevalence, the proportion of living dementia cases in the population, is the primary frequency measure used to describe the public health burden, but it does not measure disease risk. Prevalence results, roughly, from the product of incidence and disease duration. Incidence, the rate of occurrence of new disease, is critical to assessing risk and to forming causal associations with potential risk factors. Thus, consistent and reliable incidence estimates (along with methods of detecting incident cases) are necessary, both for clinicians evaluating an individual's disease risk and for researchers examining potential risk factors.