Effect of functional status on survival in patients with stroke: is independent ambulation a key determinant?

ABSTRACT

OBJECTIVE: To investigate the effect of functional status, measured using the Modified Rankin Scale (MRS), at 3 months after stroke on survival in patients with stroke. DESIGN: Cohort study. SETTING: Referral medical center. PARTICIPANTS: Patients with stroke (N=1032). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Survival after stroke. RESULTS: The Kaplan-Meier survival curves stratified by the 3-month MRS score showed 2 clear groups of patients with 3-month MRS scores of 0 to 3 (able to walk without assistance) and 4 or 5 (unable to walk without assistance). Accordingly, we grouped the patients into a high function (HF) group (3-month MRS≦3) and a low function (LF) group (3-month MRS≧4). Multiple Cox regression analysis showed that the LF group had significantly poorer survival (adjusted hazard ratio=4.69; 95% confidence interval [CI], 2.89-7.60; P<.001) than the HF group. Other significant risk factors of higher mortality were older age, history of diabetes mellitus, and heart disease. CONCLUSIONS: This study showed a significant influence of the 3-month MRS score on stroke survival. Moreover, independent ambulation may be a major determinant of a favorable survival prognosis. This finding suggests a potential role of rehabilitation in promoting stroke survival by maximizing ambulation function.