Effect Modification of Sex and Age for the Hospital Volume‐Outcome Relationship in Abdominal Aortic Aneurysm Treatment: Secondary Data Analysis of the Nationwide German Diagnosis Related Groups Statistics From 2005 to 2014

Background Trials and registries associated female sex and high age with unfavorable outcomes in abdominal aortic aneurysm treatment. Many studies showed an inverse correlation between annual hospital volume and in‐hospital mortality. The volume‐outcome relationship has not been investigated separately for women and men or across the age range. The aim was to analyze whether sex and age are effect modifiers or confounders of the volume‐outcome...