Exploring the Relationship Between Volume and Outcomes in Hospital Cardiovascular Care
Management theories of learning and experience curve effects state that greater levels of scale produce learnings and improved performance. In cardiovascular care, guidelines suggest that high-volume facilities produce better patient outcomes; yet, there are contradictory findings from the few studies conducted. Our goals were to assess the volume-outcome relationship for interventional cardiovascular care.Methods:
We examined 9360 patients with ST-segment elevation myocardial infarction who underwent percutaneous intervention (PCI). We analyzed 6 years of data (2010-2015) using systematic extracts provided by 33 PCI-capable hospitals in the Dallas Texas region from the National Cardiovascular Data Registry. We stratified hospitals into 3 procedural volume categories (low, intermediate, and high) to identify changes in 2 key outcome metrics (ie, door-to-balloon times and mortality). Multivariate analyses and tests of differences were utilized.Results:
Door-to-balloon performance outcome was significantly different between volume categories, with the highest-volume hospitals performing significantly better than intermediate- and low-volume hospitals (47, 60, and 75 minutes, respectively; P < .001). Mortality followed a similar pattern, with a 3.3% unadjusted absolute lower mortality rate for the high-volume hospitals. Multivariate regressions confirm that volume is statistically significant in both mortality and treatment times.Conclusions:
Higher-volume PCI hospitals have 37% shorter treatment times and 53% lower mortality rates than smaller facilities. This study provides evidence of a positive volume-outcome relationship in interventional cardiovascular care.