Hospital Volume of Emergency General Surgery and its Impact on Inpatient Mortality for Geriatric Patients: Analysis From 3994 Hospitals

Background Previous investigations have shown a positive association between hospital volume of operations and clinical outcomes. However, it is unclear whether such relationships also apply to emergency surgery. We sought to examine the association between hospital case volume and inpatient mortality for 7 common emergency general surgery (EGS) operations among geriatric patients. Methods This is a population based retrospective cohort study using the Centers of Medicare and Medicaid Services (CMS) Limited Dataset Files (LDS) from 2011 to 2013. The 7 most common emergency surgeries included (1) partial colectomy, (2) small-bowel resection (SBR), (3) cholecystectomy, (4) appendectomy, (5) lysis of adhesions (LOA), (6) operative management of peptic ulcer disease (PUD), and (7) laparotomy with the primary outcome being inpatient mortality. Risk-adjusted inpatient mortality was plotted against operative volume. Subsequently an operative volume threshold was calculated using a best fit regression method. Based on these estimates, high- and low-volume hospitals were compared to examine significance of outcomes. Significance was defined as P-value < .05. Results The final cohort comprised of 414 779 patients from 3994 hospitals. The standardized mortality ratio (SMR) for high-volume centers were lower in 6 out of 8 surgeries examined. Small-bowel resection and partial colectomy operations had a significant decrease in mortality based on a volume threshold. Conclusion We observed decreased mortality with higher surgical volume for small-bowel resection and partial colectomy operations. Such differences may be related to practice patterns during the perioperative period, as complications related to the perioperative care were significantly lower for high-volume centers.