Comparing processes of stroke care in high and low mortality hospitals in the West Midlands

OBJECTIVE: There are wide variations in hospital-specific mortality for stroke. The aim of this study was to investigate whether there were differences in quality of care when a group of hospitals with high standardized mortality ratios (SMRs) in nationally published league tables were compared with a group with low SMRs. DESIGN: Retrospective case note review of a random sample of patients from hospitals with high and low mortality according to published league tables. SETTING: Eight hospitals in the West Midlands, UK. PARTICIPANTS: 702 patients admitted to hospital with acute stroke during the year 2000-2001. MAIN OUTCOME MEASURES: Process measures derived from the Intercollegiate Stroke Audit Package. RESULTS: Crude 30 day mortality was 25% (99/402) in 'top' ranking hospitals and 38% (113/300) in 'bottom' ranking hospitals (P <0.001). Bottom hospitals performed significantly (P <0.001) less well on four out of seven indicators of process of care relating to the patients' first 24 hours in hospital-assessment of eye movements and visual fields, screening for swallowing disorders and sensory testing. However, analysis at the individual hospital level showed that this was largely due to poor performance in one hospital with high mortality. If this outlier was omitted, there was little relationship between process of care and SMR. No significant differences were found in care provided after 24 hours. Nevertheless even in 'top' ranking hospitals only 47% of stroke patients had at least 50% of their hospital stay in a stroke/rehabilitation unit and only 40% were on aspirin within 48 hours. CONCLUSIONS: Our results show that there is scope for improving the quality of stroke care irrespective of where a hospital ranks in terms of mortality. The lack of association between SMR and quality of care as assessed by process measures casts some doubt over the value of ranking hospitals in terms of stroke SMR.