Factors influencing in-hospital mortality and morbidity in patients treated on a stroke unit

OBJECTIVE: To determine the extent that demographics, clinical characteristics, comorbidities, and complications contribute to the risk of in-hospital mortality and morbidity in acute stroke. METHODS: Data of consecutive patients admitted to 14 stroke units cooperating within the Berlin Stroke Register were analyzed. The association of demographics, clinical characteristics, comorbidities, and complications with the risk of in-hospital death and poor outcome at discharge was assessed, and independent attributable risks were calculated, applying average sequential attributable fractions. RESULTS: In a 3-year period, 16,518 consecutive patients with ischemic or hemorrhagic stroke were documented. In-hospital mortality was 5.4%, and 45.7% had a poor outcome (modifed Rankin Scale score ≥3). In patients with length of stay (LOS) ≤7 days, 37.5% of in-hospital deaths were attributed to stroke severity, 23.1% to sociodemographics (age and prestroke disability), and 28.9% to increased intracranial pressure (iICP) and other complications. In those with LOS >7 days, age and stroke severity accounted for 44.1%, whereas pneumonia (12.2%), other complications (12.6%), and iICP (8.3%) contributed to one-third of in-hospital deaths. For poor outcome, attributable risks were similar for prestroke disability, stroke severity, pneumonia, and other complications regardless of the patient's LOS. CONCLUSIONS: Approximately two-thirds of early death and poor outcome in acute stroke is attributed to nonmodifiable predictors, whereas main modifiable factors are early complications such as iICP, pneumonia, or other complications, on which stroke unit treatment should focus to further improve the prognosis of acute stroke.