Rate and Predictors of Mortality in Elderly Nursing Home Residents with Dementia:5-Year Follow-Up Study

ABSTRACT

OBJECTIVES:To investigate mortality rates and predictors of mortality in dementia patients (prevalence cohort) resident at institution. METHODS:We followed up a dementia cohort for 5 years. A total of 273 subjects with dementia were longitudinally assessed at baseline, 6 months and 12 months and then checked whether alive or dead every 1 year for 5 years. Their mortality was compared with sociodemographic and clinical variables using Cochran-Mantel-Haenszel test and independent sample t-test. Survival time quartiles were used to describe the time until when 25%, 50%, and 75% of patients died. Kaplan Meier log-rank tests were used for testing the equality of survival among groups when identifying some disruptive agitated behaviors as mortality predictors. Relative risk (RR) with 95% confidence intervals were calculated by the Cox regression analysis. RESULTS:In this study, overall 5-year mortality rate was 63.0% (12.6% per year). Median survival after baseline evaluation was 2.85 years, whereas median survival after institutionalization was 6.42 years. Log-rank tests revealed that some disruptive behaviors (i.e., Cagras syndrome, screaming, trying to get to a different place, intentional falling) were significantly higher in the deceased group. Mortality in subjects with dementia depended on old age {over 85, relative risk (RR)1.04;95% confidence interval (CI)1.02-1.06}, male gender (RR2.04;CI1.28-3.25), lower MMSE-K score (RR1.03;CI1.00-1.06). CONCLUSION:We expect that this study may provide basic health information for health policy making in institutional care approaches in Korea