Variation in postoperative complication rates after high-risk surgery in the United States

Objective. Our goal was to characterize variation in complication rates across hospitals with differing volumes for select high-risk operations in the United States. Methods. Data from the Nationwide Inpatient Sample for 1996 and 1997 were analyzed for 3 high-risk operations: esophagectomy (n = 1,226), pancreatectomy (n = 4,789), and intact abdominal aortic aneurysm repair (n = 11,863). Complications evaluated included aspiration, cardiac complications, infection, pneumonia, pulmonary failure, renal failure, septicemia, and others. The risk of complications was calculated by hospital volume deciles, as well as for high-volume hospitals (HVH) and low-volume hospitals (LVH) defined by median hospital volume. Results. Rates of any postoperative complication varied nearly 2fold across hospital volume groups. The proportion of patients across hospital deciles having at least one complication ranged from 30% to 51% for esophageal resection, 6% to 12% for pancreatic resection, and 9% to 18% for abdominal aortic aneurysm repair. HVH had lower rates of one or more complications after pancreatic resection (OR 0.71; 95% CI, 0.57 to 0.83; P = .002), esophageal resection (OR, 0.68; 95% CI, 0.52 to 0.90; P = .008), and intact abdominal aortic aneurysm (AAA) repair (OR; 0.67; 95% CI, 0.59 to 0.76; P < .001). Patients with one or more complications after pancreatic resection had a mortality of 18.8% versus only 5.2% for those without complications (P < .001). Esophageal resection mortality was 16.9% for patients with at least one complication and 2.5% for those without complications (P < .001) and AAA repair mortality was 10.4% for patients with at least one complication and 2.9% for those without complications (P < .001). Conclusions. High-risk operations have a decreased rate of Postoperative complications when performed at HVH. Variation in complication rates may contribute to the volume-outcome relationship and provide a focus for quality improvement at LVH.