COMPARATIVE EFFECTIVENESS RESEARCH TO INFORM QUALITY IMPROVEMENT USING LINKED COSTS, OUTCOMES, AND PROCESS DATA
Method: Detailed clinical and administrative data (including pathology test results) were linked for 7,950 patients presenting with chest pain at one of four emergency departments (EDs) over a one-year period. The data were analysed using multiple regression to identify variation in costs, outcomes, and processes across hospitals. Hospital interaction terms were tested to identify patient sub-groups who might be driving variation observed at the aggregate hospital level.
Result: Statistically significant, casemix-adjusted differences were observed in mean inpatient costs (up to $672 per admitted patient), and 30 day and 12 month cardiovascular or mortality event rates (odds ratios up to 2.42 and 1.64, respectively) across providers. Larger mean differences between providers were observed for patients presenting to the ED out-of-hours and with existing circulatory conditions with respect to inpatient costs (up to $1,513 per patient), and in younger patients with respect outcomes (odds ratios up to 3.28).
Casemix adjusted analyses of process indicators identified significant differences in admission rates, particularly in older female patients, and patients with existing circulatory conditions or a positive pathology (troponin) test. Variation in the selection of patients for invasive diagnosis (angiography) was significantly larger at weekends. Differences across providers for time to admission, and for inpatient length of stay were greatest for patients with a positive troponin test.
Conclusion: The presented analyses identify clinically and statistically significant differences in casemix adjusted costs and outcomes across alternative providers, for patients presenting at an ED with chest pain. These results indicate the potential value of engaging stakeholders to identify and implement service improvements at one or more of the non-benchmark hospitals. The analyses of variation in processes provide complementary evidence to support the validity of the reported differences in costs and outcomes. The process data may also usefully inform subsequent stakeholder engagement through the identification of patient groups and process components for which variation across providers is greatest, and at which improvement efforts might be focussed.
More generally, such comparative analyses of costs, outcomes, and process across healthcare providers can inform the potential value of improving existing services (e.g. relative to allocating scarce resource to new technologies), and prioritise and guide efforts to service improvement.