Level and Change in Cognitive Test Scores Predict Risk of First Stroke

OBJECTIVES: To determine whether cognitive test scores and cognitive decline predict incidence of first diagnosed stroke. DESIGN: Stroke‐free Health and Retirement Study participants were followed on average 7.6 years for self‐ or proxy‐reported first stroke (1,483 events). Predictors included baseline performance on a modified Telephone Interview for Cognitive Status (Mental Status) and Word Recall test and decline between baseline and second assessment in either measure. Hazard ratios (HRs) were estimated using Cox proportional hazards models for the whole sample and stratified according to five major cardiovascular risk factors. SETTING: National cohort study of noninstitutionalized adults with a mean baseline age of 64±9.9. PARTICIPANTS: Health and Retirement Study participants (n=19,699) aged 50 and older. RESULTS: Word Recall (HR for 1 standard deviation difference=0.92, 95% confidence interval (CI)=0.86–0.97)) and Mental Status (HR=0.89, 95% CI=0.84–0.95) predicted incident stroke. Mental Status predicted stroke risk in those with (HR=0.93, 95%=0.87–0.99) and without (HR=0.81, 95% CI=0.72–.91) one or more vascular risk factors. Word Recall declines predicted a 16% elevation in subsequent stroke risk (95% CI=1.01–1.34). Declines in Mental Status predicted a 37% elevation in stroke risk (95% CI=1.11–1.70). CONCLUSION: Cognitive test scores predict future stroke risk, independent of other major vascular risk factors.