Characteristics and outcomes of America's lowest-performing hospitals: an analysis of acute myocardial infarction hospital care in the United States

Abstract

Background: Studies suggest that most hospitals now have relatively high adherence with recommended acute myocardial infarction (AMI) process measures. Little is known about hospitals with consistently poor adherence with AMI process measures and whether these hospitals also have increased patient mortality.

Methods and results: We conducted a retrospective study of 2761 US hospitals reporting AMI process measures to the Center for Medicare and Medicaid Services Hospital Compare database during 2004 to 2006 that could be linked to 2005 Medicare Part A data. The main outcome measures were hospitals' combined compliance with 5 AMI measures (aspirin and beta-blocker on admission and discharge and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use at discharge for patients with left ventricular dysfunction) and risk-adjusted 30-day mortality for 2005. We stratified hospitals into those with low AMI adherence (ranked in the lowest decile for AMI adherence for 3 consecutive years [2004-2006, n=105]), high adherence (ranked in the top decile for 3 consecutive years [n=63]), and intermediate adherence (all others [n=2593]). Mean AMI performance varied significantly across low-, intermediate-, and high-performing hospitals (mean score, 68% versus 92% versus 99%, P<0.001). Low-performing hospitals were more likely than intermediate- and high-performing hospitals to be safety-net providers (19.2% versus 11.0% versus 6.4%; P=0.005). Low-performing hospitals had higher unadjusted 30-day mortality rates (23.6% versus 17.8% versus 14.9%; P<0.001). These differences persisted after adjustment for patient characteristics (16.3% versus 16.0% versus 15.7%; P=0.02).

Conclusions: Consistently low-performing hospitals differ substantially from other US hospitals. Targeting quality improvement efforts toward these hospitals may offer an attractive opportunity for improving AMI outcomes.

Figure 1

Means and ranges of composite AMI scores for low-, intermediate-, and high-performing hospitals

Figure 2

Mean 30-day observed and adjusted mortality rates for low-, intermediate-, and high-performing hospitals; hospital mortality was adjusted for patient characteristics, structural hospital characteristics (eg, ownership, teaching status), and composite AMI performance score