Hospital volume, calendar age, and short term outcomes in patients undergoing repair of abdominal aortic aneurysms: the Ontario experience, 1988-92.

OBJECTIVE: To determine, for abdominal aortic aneurysm surgery, whether a previously reported relationship between hospital case volume and mortality rate was observed in Ontario hospitals and to assess the potential impact of age on the mortality rate for elective surgery. DESIGN: Population based observational study using administrative data.