Burden of mortality and morbidity from dementia

The purpose of this study was to estimate severity-specific mortality and to quantify the global health burden of dementia by assessing the time spent disabled with dementia and the life years lost due to dementia. We used mortality data from the Rotterdam study, a population-based prospective study in the 55+-year age range to calculate overall and severity-specific excess mortality for the demented. Lost life years were calculated by decomposing the (mixed) Dutch life table of 1990-1992 in two populations, the demented and the healthy, using prevalence and excess (all cause) mortality. Healthy life loss was calculated by a modified Sullivan technique, weighting for disease severity. Our results indicated that mortality was increased in the demented, in all age, sex, and severity groups. Mortality rate ratios were 2.1 (men) and 2.3 (women), with ranges of 1.7-3.4 (men) and 2.0-3.1 (women), depending on severity. Fifty-five-year-old men lose 1.2 life years due to morbidity and mortality and 0.7 life years due to mortality resulting from dementia. Women lose 3.1 and 1.9 life years, respectively. This population-based study provides evidence that mortality is increased in the demented at all stages, including minimal dementia. The quantified health impact on the general population is in the same order as that of lung cancer or stroke.