The Effects of Minimum Caseload Requirements on Management and Outcome in Abdominal Aortic Aneurysm Repair: A Secondary Analysis of German DRG Statistics Data

BACKGROUND: The German quality assurance guideline on abdominal aortic aneurysm (AAA) was implemented by the Joint Federal Committee (Gemeinsamer Bundesausschuss, G-BA) in 2008. The aims of this study were to verify the association between hospital case volume and outcome and to assess the hypothetical effect of minimum caseload requirements. METHODS: The German diagnosis-related groups statistics for the years 2012 to 2016 were scrutinized for AAA (ICD-10 GM I71.3/4) with procedure codes for endovascular or open surgical treatment. The primary endpoint was in-hospital mortality. Logistic regression models were used for risk adjustment, and odds ratios (OR) were calculated as a function of the annual hospital-level case volume of AAA. In a hypothetical approach, the linear distances for various minimum caseloads (MC) were evaluated to assess accessibility. RESULTS: The mortality of intact AAA (iAAA) was 2.7% (men [M] 2.4%, women [W] 4.2%); ruptured AAA (rAAA), 36.9% (M 36.9%, F 37.5%). An inverse relationship between annual hospital case volume of AAA and mortality was confirmed (iAAA/rAAA: from 3.9%/51% [