Stroke units in their natural habitat: systematic review of observational studies

Within clinical trials, stroke patients allocated to receive organized inpatient (stroke unit) care are more likely to survive, return home, and regain independence than those allocated to conventional care. However, there are concerns that the benefits seen in clinical trials may not be replicated in routine practice. We carried out a systematic review of observational studies of stroke unit implementation.

We searched (up to January 2006) MEDLINE, EMBASE, CINAHL, Cochrane Library, British Nursing Index, Cochrane Stroke Group register, and recent conference abstracts for observational studies that compared the outcomes of stroke patients managed in a stroke unit versus non-stroke unit care. We excluded studies that did not describe either matching for baseline prognostic factors or adjustment for case-mix characteristics. The primary outcome was death within 1 year. We also recorded poor outcome (death, institutional care, or dependency). Data analysis used the generic inverse variance method in Revman 4.2. Where raw data were provided, effect sizes and variances were calculated accordingly. We used a random-effects model and explored for sources of heterogeneity.

We identified 72 articles describing stroke unit outcomes; 25 were eligible for review; and 18 provided data on case fatality or poor outcome. Stroke unit care was associated with significantly reduced odds of death (odds ratio=0.79, 95% CI=0.73 to 0.86; P<0.00001) and of death or poor outcome (odds ratio=0.87, 95% CI=0.80 to 0.95; P=0.002) within 1 year of stroke. Results were complicated by significant heterogeneity (P<0.05), mainly in single-center studies.

Although these results are complicated by potential bias and heterogeneity, the observed benefit associated with stroke unit care in routine practice is comparable to that in clinical trials.