Delirium: A predictor of mortality in the elderly

Abstract

The frequency of delirium in elderly inpatients is high, resulting in poor hos- pital outcomes. The objective of this study is to assess whether delirium is an independent predictor for mortality over a three-month period. Methods :P rospective, observational study in a cohort of 171 inpatients aged over 65 years. Presence of delirium and/or dementia, severity of delirium and incapacity due to ill- ness were assessed at baseline using DSM-IV diagnostic criteria, the Confusion Assessment Method (CAM), the MMSE, the Delirium Rating Scale (DRS) and the Karnofsky Perfor- mance Status (KPS). Mortality rates were evaluated over a three-month follow-up period after enrollment. Kaplan-Meier survival curves were constructed and the adjusted effect of a set of covariates was evaluated with the Cox multiple regression analysis. Results: By 3 months after enrollment, 34.4% of the patients with delirium died, compared with 16.5% of those without delirium. The survival analysis shows a statistically significant difference between the two groups (log-rank=11.92; d.f.=1; P=0.0006). After adjustment for covariates, delirium was found to be independently associated with higher mortality. Conclusions: Delirium was found to be an independent marker for mortality in older medical patients over a three-month follow-up.