Predictors of mortality among demented elderly in primary care

Objectives. To evaluate a wide range of sociodemographic, neurological and clinical variables as to whether they predict mortality in a representative sample of demented elderly. Design. A three-stage community survey was conducted,based on a total of 37 21 elderly patients whose cognitive status was assessed by their general pr actitioners (stage I). A stratified random sample of patients underwent a s tandardized research interview, including cognitive testing and the assessm ent of mental status, physical illness, sensory impairment and motor disabi lity (stage II). After a mean interval of 28 months, all patients were reco ntacted. For deceased patients a close reference person was interviewed and the exact date of death was recorded (stage III). The influence of the pre dictor variables on mortality was determined by using the Cox proportional hazards model. Subjects. A stratified random sample of 117 patients in primary care (mean age 82 years) suffering from mild, moderate or severe dementia (Alzheimer t ype, vascular or mixed dementia). Materials. Hierarchical Dementia Scale (HDS), a modified version of the Ham ilton Depression Scale, other clinical rating scales and CAMDEX criteria fo r clinical diagnosis and a degree of severity of dementia. Results. Fifty-three of the 117 demented patients had died during the follo w-up interval. The mortality risk increased steeply with the degree of seve rity of dementia. By controling for this variable, only age and motor disab ility contributed significantly to the prediction of mortality,whereas gend er, social class, type of dementia, extrapyramidal signs and other clinical features showed no or only a weak effect on the outcome. Conclusion. The remaining Life expectancy of the demented elderly depends p rimarily on the severity of the dementia, the patients' age and their gener al physical health. The influence of other clinical features which often ha ve been hypothesized as indicators of specific subgroups of dementia was ma inly due to their relationship to the disease severity. Copyright (C) 1999 Jobs Wiley & Sons, Ltd.