Cognitive functioning predicts survival in the elderly

Prior studies of aging have identified a number of predictors of survival, including performances on some cognitive-functioning tests. However, few studies have used a multidomain test battery to identify which specific cognitive abilities predict death. The current study examined the 12 subtests of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to see which subtests predicted death in a sample of 796 older, primary care patients. After 4 years, 98 individuals died, and 698 individuals remained alive. The individuals who died performed more poorly at baseline on 9 of the 12 RBANS subtests (p <.05) than did their peers who remained alive. In a multivariate analysis, however, only the RBANS Coding subtest independently predicted death (p <.001), along with male gender and greater initial medical comorbidity. Although the mechanism of poorer cognition and impending death remains unclear, some possibilities are discussed (e.g., brain dysfunction, poor medical compliance, impaired cellular immunity).