Predictors of 49-month mortality in Chinese nonagenarians and centenarians in PLAD study.

Abstract

To examine whether a set of well-known predictors of mortality in younger elderly also maintain their importance in Chinese oldest old group. A cross-sectional study of 1401 inhabitants aged 90 and older were conducted in the area of Dujiangyan, China. 825 subjects participated and were followed up for vital status after 49 months. Professional interviewers collected baseline data concerning socio-demographic characteristics, lifestyle habits, physical factors and geriatric assessment. Bivariate analysis was conducted between survivors and deceased. Cox regression models were used to evaluate predictors of mortality. Four hundred and thirty-six (52.8%) of 825 participants eligible for the analysis died during the 49 months of follow-up period. Older age, comorbidity, lower MMSE score, lower ADL and IADL scores increased the risk of mortality in the study group. Multivariate analyses showed older age (HR = 1.03, 95% CI 1.01-1.07) and comorbidity (HR = 1.09, 95% CI 1.02-1.17) were associated with mortality while female gender (HR = 0.61, 95% CI 0.43-0.86), taking exercise (HR = 0.80, 95% CI 0.64-1.01) and higher MMSE scores (HR = 0.96, 95% CI 0.94-0.99) showed a positive effect on survival. In Chinese nonagenarians and centenarians, age, gender, taking exercise, cognitive impairment and comorbidity at baseline show predictive power of oldest old mortality.