Causes of death by level of dependency at 6 months after ischemic stroke in 3 large cohorts.

Abstract

We assessed the influence of functional status at 6 months after ischemic stroke on cause of death during long-term follow-up in 3 prospective cohorts. The cohorts were 7710 patients from the Oxfordshire Community Stroke Project, Lothian Stroke Register, and International Stroke Trial. Functional status was assessed at 6 months after stroke onset. Causes of death were identified from death certificates, and were also classified into "stroke-related" or "other" causes. We calculated the relative risk with 95% CI to assess the association between dependency level and cause of death. We also performed a multivariable regression analysis to adjust for other relevant factors. Six months after stroke onset 5961 (78%) patients were still alive. At the end of follow-up period, 1620 (47%) patients who were functionally dependent at 6 months after stroke onset had died vs 711 (28%) independent patients. Dependent patients had a relative risk of dying from stroke of 1.70 (95% CI, 1.44-2.00) compared to independent patients. Overall, dependent patients had a relative risk of 1.68 (95% CI, 1.49-1.91) of dying from stroke-related causes. Dependency remained significantly (P<0.01) associated with stroke-related causes of death in a multivariable regression analysis. Stroke-related deaths continue to be a problem during the years after an ischemic stroke, especially in patients who are functionally dependent at 6 months after onset. Better acute treatments to reduce dependency and adequate secondary prevention remain high priorities.