Functional outcome 3 months after stroke predicts long-term survival

Background: When reporting stroke survival and prognostic factors with a possible effect on outcome, the starting point for the observation of a clinical cohort usually is the onset of stroke or the acute admission of a patient. Thus, acute and early mortality inflict prognosis on long-term outcome. In order to give a more robust analysis of long-term survival after the acute period we chose to start our observation with 3-month survivors. Methods: We used data from Riks-Stroke, the Swedish quality register for stroke care, together with survival information from the Swedish population register to explore the influence of disability level 3 months after stroke on long-term survival. The main analysis included 15,959 stroke patients, registered during 2001-2002, who had been independent in primary activities of daily living before stroke, had suffered an ischaemic or a haemorrhagic stroke and reported no previous stroke. Results: Impaired functional outcome after stroke was an independent predictor of poor survival. Patients with modified Rankin scale (mRS) grades 3, 4 and 5 had hazard ratios of 1.7, 2.5 and 3.8, respectively, as compared with patients with lower mRS grades. In addition to high mRS, male sex, high age, diabetes, smoking, hypertension therapy at stroke onset, atrial fibrillation and depressed mood were also recognized as significant predictors of poor survival using a multiple Cox regression model. Conclusion: The influence of disability on survival is stronger than that of several other well-known prognostic factors. This finding indicates that any intervention in the acute phase that may improve functional status at 3 months will also have favourable secondary effects on survival in the long term. Copyright (C) 2008 S. Karger AG, Basel.