National variation in operative mortality rates for esophageal resection and the need for quality improvement

Hypothesis: Operative mortality rates for esophageal resection vary across hospital volume groups in a nationally representative sample of hospitals. Design: Cross-sectional study of all adult patients in the Nationwide Inpatient Sample who underwent esophageal resection from 1995 through 1999 (N = 3023). Operative mortality was determined for hospital volume quartiles (low, <3 per year; medium, 3-5 per year; high, 6-16 per year; very high, > 16 per year). Multiple logistic regression of in-hospital mortality was used for case-mix adjusted analyses. Setting: Hospitals performing at least 1 esophageal resection from 1995 through 1999 in the Nationwide Inpatient Sample. Patients: Patients having esophageal resection from 1995 through 1999 in the Nationwide Inpatient Sample. Results: Overall mortality was 8.2% and varied 3-fold from 11.8% to 3.7% across hospital volume groups (P<.001). In the case-mix-adjusted multivariate analysis, having surgery at a low-volume hospital (odds ratio, 2.9; 95% confidence interval, 1.7-4.9; P<.001) or medium-volume hospital (odds ratio, 2.4; 95% confidence interval, 1.4-4.3; P=.002) was associated with an increased risk of mortality compared with the reference group of very high-volume hospitals. The effect of volume on mortality was significant for both malignant and benign disease. Given the absolute risk difference of 8.1% between very high- and low-volume hospitals, only 12 patients would need to be referred to prevent 1 death after esophageal resection. Conclusions: The operative mortality rate for esophageal resection varies across hospitals in the United States. To improve the quality of care and reduce operative mortality rates for patients in need of esophageal surgery, patients should either be referred to higher-volume hospitals, or quality improvement should be directed at lower-volume hospitals.