Determinants of Health Status After Stroke: A Cohort Study with Repeated Measurements

Background: Knowledge about the long-term course of health following stroke is sparse and relies mainly on studies with short follow-up or few measurements per patient. We aimed to describe the course and analyze the determinants of the course of physical and mental health status after stroke with repeated measurements in a large population-based cohort of first time Danish stroke patients. Methods: We followed 2,414 first time stroke patients admitted to any hospital in the Central Denmark Region, Denmark, between October 1, 2008 and January 1, 2012, with five questionnaires over a 2 years period. Self-rated health was assessed by the SF-12 instrument. Information on possible clinical and patient-related determinants of self-rated health was obtained from questionnaires and national registers. The scores were analyzed at five selected fixed time-points and as well as longitudinally with mixed models. Results: The SF-12 mental component summary score (MCS) increased with 0.89 points/year (95% CI=0.6-1.2), while the increase in the physically component summary score (PCS) did not reach statistical significance (0.13/year, 95% CI=-0.2-0.5). The most pronounced changes were seen in the Vitality and Role Physical SF-12 subscales, which both increased by 2.1 points/year. No statistically significant changes over time were found in the Physical Functioning and Bodily Pain subscales. Variables associated with increasing self-rated mental health (MCS) were no comorbidity, older age, male gender, and mild stroke severity. Variables associated with increasing ratings of physical health (PCS) were mild stroke severity, no comorbidity, higher educational level, and younger age. The negative impact of age increased significantly with time during the follow-up period for physical as well as mental health, while the effects of the other variables were stable over time. The results were similar in the two analytical approaches. Conclusion: In a large, geographically well-defined population of first time stroke patients, the majority of SF-12 sub-scales and the mental component score improved slightly over time. Small improvements in self-rated mental health may be observed during the first 2 years after the stroke. Stroke is a disease with long-term consequences on a wide range of health aspects. Level as well as course differ between sub-groups, and treatment of comorbidity may be an important target with respect to rehabilitation.