Reduction of in-hospital mortality among California hospitals meeting Leapfrog evidence-based standards for abdominal aortic aneurysm repair

Abstract

The Leapfrog Group established evidence-based standards for abdominal aortic aneurysm (AAA) repair, including targets for case volume and perioperative beta-blocker usage. The purpose of this study was to determine whether meeting these benchmarks correlated with improved patient outcomes over time. We studied California hospitals that responded to consecutive Leapfrog Group Hospital Quality and Safety Surveys between 2000 and 2005. Survey results of compliance with Leapfrog standards were linked to patient outcomes for AAA repair using the California state discharge database for the corresponding years. A random-effects Poisson regression analysis was performed to measure the effect of meeting beta-blocker and case volume standards on hospital mortality and average length of stay after elective open and endovascular AAA repair (EVAR) during the early (2000-2002) and later (2003-2005) phase of Leapfrog implementation. Among 140 hospitals that performed open AAA repair, 25 (17.4%) met the Leapfrog case volume standard, 32 (22.2%) were compliant with routine perioperative beta-blocker use, 5 hospitals (3.5%) met both criteria, and 78 control hospitals failed to meet either standard. After controlling for temporal differences in hospital and patient characteristics, hospitals that implemented a policy for perioperative beta-blocker usage were found to have an estimated 51% reduction of in-hospital mortality (relative risk, 0.49; 95% confidence interval, 0.24-0.99; P < .05) after open AAA repair cases compared with control hospitals over time. There was no improvement in mortality outcomes over time, however, after open AAA repair in hospitals meeting case volume standards. Among 111 California hospitals in which EVAR was performed, there was an estimated 61% reduction of in-hospital mortality over time (relative risk, 0.39; 95% confidence interval, 0.07-1.80) among hospitals meeting Leapfrog case volume standards compared with control hospitals, although these results did not reach statistical significance. Finally, there was no reduction in length of hospital stay over time after either EVAR or open AAA repair for hospitals meeting Leapfrog standards compared with control hospitals. This population-based study supports the effectiveness of meeting Leapfrog AAA repair standards towards improving mortality outcomes over time and suggests that their impact depends upon procedure type. Further studies are needed to help promote the standardization of evidence-based measures that may improve vascular surgery outcomes.