Cognitive predictors of mortality in elderly retirees: results from the Freedom House study.

OBJECTIVE

The objective of this longitudinal cohort study was to study the cognitive domains associated with five-year longitudinal survival among healthy, well-educated, noninstitutionalized elderly.

METHODS

Survival curves were generated as a function of cross-sectional baseline cognitive test performance.

RESULTS

Nonverbal tests were significantly associated with survival. This finding was markedly consistent. Several nonverbal tasks were each significantly associated with survival independently of age, gender, baseline level of care, and healthcare utilization. In a multivariate model, copying a clock made the strongest, independent contribution to survival.

CONCLUSIONS

Right hemisphere integrity in general and nonverbal drawing tasks in particular have been associated with survival in conditions as diverse as Alzheimer disease, stroke, and epilepsy. This study extends this association to "normal" aging. The mechanism by which nonverbal cognitive function is related to mortality remains unclear but may be mediated by changes in right hemisphere cortical control of autonomic function. Nondemented older persons may be at risk. Clock drawing may provide a simple means of identifying them.