The Relationship Between Hospital Volume and Mortality for Acute Pancreatitis in the United States

Objectives: Previous reports demonstrate conflicting findings regarding the relationship between mortality and hospital volume for acute pancreatitis (AP). Here we seek to reevaluate the impact of hospital admission volume on AP-specific mortality based on disease severity. Methods: Patient demographics, clinical data, and hospital factors were collected from the Nationwide Inpatient Sample (NIS) for patients with AP between 2008–2011. Hospitals were divided into five volume groups based on the number of admissions for AP and severe acute pancreatitis (SAP) per year. The relationship between hospital volume and outcomes was evaluated with the primary endpoint being in-hospital mortality. Logistic regression was used to identify factors associated with mortality. Results: Data from 182,331 admissions for AP were included in the analysis. The median number of annual hospital admissions per year was 35. SAP was present in 18,708 patients. There were no differences in-patient mortality by hospital volume groups for AP (0.69–0.94%, p = 0.19) or SAP (5.43–7.21%, p = 0.06). Factors found to be associated with increased risk of inpatient mortality included age ≥ 75 (OR: 5.18, CI 4.33–6.20), male gender (OR: 1.30, CI 1.17–1.44) comorbidities (OR: 3.77, CI: 2.61–5.44), and SAP (OR: 17.7, CI: 15.7–19.9). Conclusions: Hospital volume of AP and SAP does not appear to be associated with inpatient mortality. Increasing age, male gender, comorbidities, and SAP are associated with increased risk of mortality. The complex relationship between hospital volume, disease severity and disparities in health care delivery and outcomes requires further scrutiny.