OVER trial analysis shows lower hospital costs for EVAR but no difference after two years


A cost-effectiveness analysis of the OVER trial has shown that endovascular repair of abdominal aortic aneurysms (EVAR) resulted in lower costs and improves survival than open repair after the initial hospitalisation period. However, after two years there was no statistically significant difference between the two techniques.

The cost-effectiveness analysis of the OVER (Open versus endovascular repair) Veterans Affairs (VA) Cooperative Study was published in the October 2012 issue of the Journal of Vascular Surgery. The cost-effectiveness study was conducted by Kevin Stroupe, Frank Lederle, Jon Matsumura, Tassos Kyriakides, Yvonne Jonk, Ling Ge, and Julie Freischlag.

The OVER study was a US multicentre trial, which randomised 881 patients (aged ≥49 years) to elective EVAR (n=444) or open repair (n=437) in 42 Veterans Affairs Medical Centers. Lederle is the principal investigator in the trial.

The primary outcomes of the cost-effectiveness analysis were mean total healthcare cost per life-year and per quality-adjusted life-year from randomisation to two years after.

The authors explained that quality-adjusted life-years were calculated from EuroQol-5D questionnaires, collected at baseline and annually, and explained that healthcare utilisation data were obtained directly from patients and from national VA and Medicare data sources. They added, “VA costs were obtained from national VA sources using methods previously developed by the VA Health Economics Resource Center. Costs for non-VA care were determined from Medicare claims data or billing data from the patient’s healthcare providers.”

The results showed that mean graft costs were higher in the endovascular group (US$14,052 vs. US$1,363; p<0.001), but length of stay was shorter (5 vs. 10.5 days; p<0.001), resulting in a lower mean cost of the hospital admission for the abdominal aortic aneurysm procedure in the endovascular repair group of US$37,068 vs. US$42,970 (p=0.04).

After two years of follow-up, mean life-years were 1.78 in the EVAR group and 1.74 in the open repair group (p=0.29). Mean quality-adjusted life-years were 1.462 in the endovascular group and 1.461 in the open group (p=0.78).

The authors wrote that, after two years, “Total healthcare costs remained lower in the endovascular group, but the difference was no longer significant (p=0.35). The probability of endovascular repair being less costly and more effective was 70.9% for life-years and 51.4% for quality-adjusted life-years.”

They concluded, “In this multicentre randomised trial, endovascular aneurysm repair resulted in lower cost and better survival than open repair after the initial hospitalisation for repair; but after two years, survival, quality of life, and costs were not significantly different between the two treatments.”