Cost-effectiveness analysis of elective endovascular repair compared to open surgical repair of abdominal aortic aneurysms.

DeRose G, Bowen J, Blackhouse G, Novick T, Forbes TL, Lawlor DK, Harris KA, Goeree R
Division of Vascular Surgery, London Health Sciences Centre, University of Western Ontario, PATH, McMaster University

Objective: Clinical outcomes, resource utilization and quality of life information on patients undergoing elective abdominal aortic aneurysm (AAA) repair was collected prospectively in order to compare patients treated with an endovascular approach (EVAR) to open standard repair (OSR) and determine cost-effectiveness.

Methods: After IRB approval, all patients requiring elective repair of an AAA  were invited to participate in a non-randomized, prospective observational study. Informed consent was obtained from all subjects before study participation.  At baseline, demographic and medical data as well as quality of life information was collected from participating subjects.  Subsequent data collection regarding surgical outcomes and resource use were obtained for the peri-operative and post-operative periods.  Patient- specific costing information was also obtained from initial hospitalization to discharge.  Subsequent resource utilization data at 30 days post-surgery and every three months post surgery for 1 year were obtained. 

Results: Between August 11, 2003 and April 3, 2005 at London Health Sciences Centre, 140 EVAR and 195 OSR patients  were enrolled in the study.  Based on a scale of co-morbidities, all patients treated with EVAR were stratified as high risk; of the patients undergoing OSR, 52 patients were considered high surgical risk (OSR high risk) and 143 low surgical risk (OSR low risk).  The peri-operative mortality rate was 0.7% for EVAR and 9.6% for OSR high risk. The mean initial hospitalization costs were $28,139 for EVAR compared to $15,494 for OSR low risk and $31,181 for OSR high risk. The average one year medical cost of follow-up was significantly greater for EVAR patients ($5,181) than OSR patients ($1,965). Productivity losses were not significantly different. The total mean 1 year cost of EVAR patients was $34,146, which compared to $23,165 for all OSR patients. However, when EVAR patients are compared with OSR high risk ($34,170) the difference was negligible (-$24).
The estimated number of life years gained as determined from the Kaplan Meier survival curves for EVAR and OSR high risk patients were 0.959 and 0.848, respectively.  The Quality Adjusted Survival curves and the resulting quality adjusted life years (QALYs) for EVAR and OSR were calculated to be 0.713 and 0.688, respectively.

Conclusions: For patients at high risk, EVAR is a safe and effective procedure with fewer complications and mortality occurring in EVAR patients compared to OSR patients with similar baseline risks.  The total hospitalization costs associated with EVAR compared to OSR high risk patients are less and differences in the mean annual 1 year health related costs are negligible. EVAR had 0.111 more life years gained compared to OSR high risk patients.