Comorbidity and the increased mortality after hospitalization for stroke: a population‐based cohort study

Abstract

Background Comorbidity is prevalent among stroke patients, affecting post-stroke survival. It remains unknown whether comorbidity impacts post-stroke mortality beyond the combined individual effects of stroke and comorbidity. Methods Using nationwide Danish databases, we performed a cohort study of 201 691 patients ≥ 18 years old with incident ischemic stroke, intracerebral or subarachnoid hemorrhage, or unspecified stroke during 1995-2012, and 992 942 adults from the general population, matched to stroke patients by birth year, sex and individual comorbidities in the Charlson Comorbidity Index. During up to 5 years of follow-up, we computed standardized mortality rates (SMRs) to assess interaction contrasts as a measure of excess mortality not explained by the additive effects of stroke and comorbidity acting alone. Results Five-year post-stroke mortality was 48%, corresponding to an SMR of 187 deaths per 1000 person-years. During the 30-day peak post-stroke mortality (SMR, 180 per 1000 person-months), interaction with comorbidity represented 23%, 34% and 51% of post-stroke mortality rates among patients with low (score = 1), moderate (score = 2-3) and high (score = 4+) comorbidity based on Charlson Comorbidity Index scores. The interaction accounted for 5% to 32% of subsequent 31-365-day post-stroke mortality rates, depending on comorbidity level. The interaction contrasts were most notable among comorbid patients with cancer, particularly with hematological or metastatic disease, followed by patients with moderate-to-severe liver or renal disease. Conclusion Comorbidity, notably cancer and advanced renal or liver disease, increased 1-year mortality after stroke beyond the combined effects expected from either disease acting alone.

Association between Clinical and Laboratory Markers and 5-year Mortality among Patients with Stroke

“…Corraini et al . showed that a higher CCI score resulted in higher post-stroke mortality in patients with stroke during the first year of follow-up 43 . Schmidt et al .…”

Multimorbidity in Stroke

“…increased one year mortality after stroke beyond the combined individual effects of stroke or the comorbidity 18 . Two community studies (in the United States and Spain) found that multimorbidity measured by CCI was a significant predictor of six-month mortality in stroke patients 19,20 .…”

Sex Differences in Long-Term Mortality and Functional Outcome After Rehabilitation in Patients With Severe Stroke

“…The covariates examined included age (per 5-year increase above 65), marital status (married/not married), hypertension, diabetes, COPD, history of CAD, AF, anemia, renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m2), time from stroke onset to rehabilitation admission <30 days, ischemic stroke, dysphagia, neglect, motor FIM score at admission, and cognitive FIM score at admission. These variables were selected based on availability at time of presentation and prior studies showing an association with the outcomes of interest (4,6,11,12,17,(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32) and were included in all analyses.…”

“…Approximately 20-25% of stroke survivors present severe disability (3). Comorbidity is prevalent in stroke patients and affects both life expectancy and disability (4).…”