The diagnosis of abdominal aortic aneurysms (AAA) has become increasingly common and is caused by increased physician awareness as well as improved imaging techniques. 1 More than 40,000 procedures are performed each year in the United States, 2 resulting in an annual incidence of more than 35 procedures per 100,000 population. 3 At an estimated cost of $25,000 per procedure, 4 more than $1 billion is spent each year in the United States on AAA repair. As AAA repair has become more common, it has also become safer, with average mortality rates now ranging from 4.8% to 6.8%. 5-8 However, AAA repair is still associated with significant perioperative morbidity and mortality, 5,7,9,10 and more than 80% of perioperative complications are associated with coronary artery disease. 5 Patients with perioperative complications often have exorbitant in- hospital costs. Although a number of studies have examined the predictors of adverse clinical outcomes associated with AAA repair, 7,11-13 few of these studies have examined the impact of perioperative events on in-hospital cost. Thus the objective of this study was to examine the correlates of in-hospital cost among patients undergoing AAA repair. Methods Study patients We examined a retrospective cohort of 71 patients who underwent AAA repair at the Cleveland Clinic over a 1-year period (December 1993 to December 1994). Most patients were referred for elective surgical repair; however, a small number of patients required urgent or emergent procedures because of a ruptured aneurysm or an acute dissection. Patients were identified through the Transition Systems Inc. (TSI) database (Boston, Mass.) at the Cleveland Clinic. 14 This system maintains cost data on all patients admitted to the Cleveland Clinic, and it allows for the identification of patients by diagnostic-related groups. Outcomes, Health Policy, and Managed Care Correlates of in-hospital cost among patients undergoing abdominal aortic aneurysm repair Bruno S. Benzaquen, MD, Mark J. Eisenberg, MD, MPH, Ram Challapalli, MD, Thanh Nguyen, DO, Kimberly J. Brown, RN, and Eric J. Topol, MD Cleveland, Ohio, and Montreal, Quebec, Canada Background Surgical repair of abdominal aortic aneurysms (AAA) is increasingly being performed, but little is known about the correlates of in-hospital cost associated with this procedure. Methods and Results Baseline clinical characteristics, in-hospital outcomes, and total in-hospital costs were exam- ined among a retrospective cohort of 71 patients who underwent AAA repair. Median age was 68 years, and 75% of the patients were men. High-risk characteristics for perioperative complications were common and included hypertension (73%), documented coronary artery disease (66%), smoking (60%), previous myocardial infarction (47%), history of congestive heart failure (12%), urgent or emergent AAA repair (16%), and diabetes mellitus (11%). Perioperative complications included congestive heart failure (13%), myocardial infarction (11%), and death (1%). Median length of stay in the surgical intensive care unit (SICU) was 2 days (range 0 to 28), and median in-hospital stay was 9 days (range 5 to 39). In-hospital cost for the 71 patients ranged from $13,766 to $82,435 (mean $25,931, median $21,633). Univariate and multiple lin- ear regression analyses demonstrated that among the potential correlates investigated, number of SICU days (P = .007) and total length of stay (P < .0001) were the most closely associated with in-hospital cost. Conclusions Among patients undergoing AAA repair, the major correlates of in-hospital cost are the number of days spent in the SICU and the total number of days spent in the hospital. These results suggest that any intervention that reduces length of stay may significantly reduce the total in-hospital cost associated with AAA repair. (Am Heart J 1998;136:696-702.) From the Department of Cardiology, Cleveland Clinic Foundation, and the Divisions of Cardiology and Clinical Epidemiology, Jewish General Hospital. Submitted Sept. 27, 1997; accepted Feb. 26, 1998. Reprint requests: Mark J. Eisenberg, MD, MPH, Division of Clinical Epidemiology, Suite A-120, Jewish General Hospital/McGill University, 3755 Cote Ste-Catherine Road, Montreal, Quebec H3T 1E2, Canada. Copyright © 1998 by Mosby, Inc. 0002-8703/98/$5.00 + 0 4/1/90603