Cost-effectiveness of surgery for small abdominal aortic aneurysms on the basis of data from the United Kingdom small aneurysm trial

Purpose: Although the United Kingdom small aneurysm trial reported no survi val benefit for early operation in patients with small (4.0-5.5 cm) abdomin al aortic aneurysms (AAAs), the trial lacked statistical power to detect sm all but potentially meaningful gains in life expectancy, particularly for s pecific subgroups, me used decision analysis to better characterize the pot ential benefits and cost-effectiveness of early surgery. Methods: We used a Markov model to assess the marginal cost-effectiveness ( incremental cost per quality-adjusted life year [QALY] saved) of early surg ery relative to surveillance for small AAAs, using data from the UK Trial. Subgroup analyses were performed by patient age and AAA diameter. Sensitivi ty analysis was used to evaluate the effect of elective operative mortality on cost-effectiveness. Results: In our baseline analysis, early operations provided a small surviv al advantage (0.14 QALYs) at a small incremental cost of $1510. Thus, despi te a small survival benefit, early surgery appeared cost-effective ($10,800 /QALY). The small cost differential resulted from the large proportion of p atients who underwent surveillance, who eventually underwent AAA repair, an d therefore incurred the cost of the surgical procedures. The survival adva ntage and cost-effectiveness of early operation increased with lower operat ive mortality, younger age, and larger AAA diameter. Conclusion: Despite the negative conclusions of the UK trial, early surgery may be cost-effective for patients with small AAAs, particularly younger p atients (<72 years of age) with larger AAAs (greater than or equal to 4.5 c m). Because the gains in: life expectancy are relatively small, however, cl inical decision making should be strongly guided by patient preferences.