Stroke unit care revisited: who benefits the most? A cohort study of 105 043 patients in Riks-Stroke, the Swedish Stroke Register

BACKGROUND: Treatment at stroke units is superior to treatment at other types of wards. The objective of the present study is to determine the effect size of stroke unit care in subgroups of patients with stroke. This information might be useful in a formal priority setting. METHODS: All acute strokes reported to the Swedish Stroke Register from 2001 through 2005 were followed until January 2007. The subgroups were age (18-64, 65-74, 75-84, 85+ years and above), sex (male, female), stroke subtype (intracerebral haemorrhage, cerebral infarction and unspecified stroke) and level of consciousness (conscious, reduced, unconscious). Cox proportional hazards and logistic regression analyses were used to estimate the risk for death, institutional living or dependency. RESULTS: 105,043 patients were registered at 86 hospitals. 79,689 patients (76%) were treated in stroke units and 25,354 patients (24%) in other types of wards. Stroke unit care was associated with better long-term survival in all subgroups. The best relative effect was seen among the following subgroups: age 18-64 years (hazard ratio (HR) for death 0.53; 0.49 to 0.58), intracerebral haemorrhage (HR 0.61; 0.58 to 0.65) and unconsciousness (HR 0.70; 0.66 to 0.75). Stroke unit care was also associated with reduced risk for death or institutional living after 3 months. CONCLUSIONS: Stroke unit care was associated with better long-term survival in all subgroups, but younger patients, patients with intracerebral haemorrhage and patients who were unconscious had the best relative effect and may be given the highest priority to this form of care.