A Cost Effectiveness Analysis of Outpatient versus Inpatient Hospitalisation for Lower Extremity Arterial Disease Endovascular Revascularisation in France: A Randomised Controlled Trial

Objective: The AMBUVASC trial evaluated the cost effectiveness of outpatient vs. inpatient hospitalisation for endovascular repair of lower extremity arterial disease (LEAD). Methods: AMBUVASC was a national multicentre, prospective, randomised controlled trial conducted in nine public and two private French centres. The primary endpoint was the incremental cost effectiveness ratio (ICER), defined by cost per quality adjusted life year (QALY). Analysis was conducted from a societal perspective, excluding indirect costs, and considering a one month time horizon. Results: From 16 February 2016 to 29 May 2017, 160 patients were randomised (80 per group). A modified intention to treat analysis was performed with 153 patients (outpatient hospitalisation: n = 76; inpatient hospitalisation: n = 77).The patients mainly presented intermittent claudication (outpatient arm: 97%; inpatient arm: 92%). Rates of peri-operative complications were 20% (15 events) and 18% (14 events) for the outpatient and inpatient arms respectively (p = .81). Overall costs (difference: (sic)187.83; 95% confidence interval [CI] -275.68-651.34) and QALYs (difference: 0.00277; 95% CI -0.00237 - 0.00791) were higher for outpatients due to more re-admissions than the inpatient arm. The mean ICER was (sic)67 741 per QALY gained for the base case analysis with missing data imputed using multiple imputation by predictive mean matching. The outpatient procedure was not cost effective for a willingness to pay of (sic)50 000 per QALY and the probability of being cost effective was only 59% for a (sic)100 000/QALY threshold. Conclusion: Outpatient hospitalisation is not cost effective compared with inpatient hospitalisation for endovascular repair of patients with claudication at a (sic)50 000/QALY threshold.