Real-world cost analysis of endovascular repair versus open repair in patients with nonruptured abdominal aortic aneurysms

Abstract

Background: The aim of this study was to provide a nationwide, all-payer, real-world cost analysis of endovascular aortic aneurysm repair (EVAR) versus open aortic aneurysm repair (OAR) in patients with nonruptured abdominal aortic aneurysms (non-rAAA).

Methods: All non-rAAA patients registered between July 2009 and March 2015 in the Premier Healthcare Database were analyzed. The Student t-test and the χ² test were used for continuous and categorical variables, respectively; median value comparisons were done with the Wilcoxon-Mann-Whitney rank-sum test. The in-hospital absolute mean total cost (sum of fixed cost and variable cost) and subcategories were analyzed after adjustment for inflation at July 2015. Fixed costs included all overhead costs while variables costs included in-hospital services including procedures, room and board, services provided by hospital staff, and pharmacy costs. Total cost was stratified based on admission type (emergency vs nonemergency), 75th percentile of length of hospital stay among individual procedures (expected vs extended stay), mortality, and complications. Student t-test and Fisher's analysis of variance were used for comparing mean cost. Year-wise comparison of mean cost was done with analysis of variance to look for a trend over time.

Results: Our study cohort included 38,809 non-rAAA patients (33,171 EVAR and 5638 OAR). The mean total cost of index admission was lower in EVAR in comparison with OAR ($32,052 vs $36,091; P < .001), with lower fixed costs ($11,309 vs $16,818; P < .001) and higher variable costs ($20,743 vs $19,272; P < .001). Cost of pharmacy, labor, operating room, room and board and other costs were significantly higher with OAR, whereas the supply cost was higher with EVAR. The expected hospital length of stay of patients who underwent EVAR was associated with a higher total cost ($27,271 vs $25,680; P < .001) and a higher variable cost ($18,186 vs $13,671; P < .001) than OAR patients. However, the extended hospital stay of patients who underwent EVAR had lower costs in all categories compared with the extended length of stay of those who underwent OAR. Mortality associated with EVAR was costlier than OAR associated mortality (mean $72,483 vs $59,804; P = .017). From 2009 to 2014, the mean total cost of EVAR increased significantly by 18.5% ($28,745 vs $34,049; P < .001) owing to a 7.8% increase in fixed costs ($10,931 vs $11,789; P < .001) and a 25.0% increase in variable costs ($17,804 vs $22,257; P < .001). The mean total cost OAR remained stable over time.

Conclusions: Overall hospitalization costs associated with EVAR of non-rAAA was lower than the hospitalization cost of OAR. Interestingly, we found that, among patients who had an expected hospital length of stay, the hospitalization cost after OAR was significantly lower than after EVAR. The average hospitalization cost of OAR was stable during the 5 years study period, whereas the hospitalization cost of EVAR increased significantly over time. Further studies are required to identify reasons for increased costs associated with EVAR.

Keywords: Cost analysis; EVAR; Nonruptured AAA; length of stay.