Cost-effectiveness Analysis of Ankle-Brachial Index Screening in Patients With Coronary Artery Disease to Optimize Medical Management

Abstract

Currently, screening for peripheral artery disease (PAD) with the ankle-brachial index (ABI) test is not recommended in the general population; however previous studies advocate screening in high risk populations. Although providers may be hesitant to prescribe patients low dose rivaroxaban in patients with coronary artery disease (CAD) we hypothesize that screening patients for PAD may provide additional evidence to prescribe rivaroxaban given the additional benefits of reducing cardiovascular events and death. We sought to describe the cost-effectiveness of screening for PAD in patients with CAD to optimizing medical management of these patients. We used a Markov model to evaluate the ABI test in patients with CAD. We assume that all patients screened would be candidates for low dose rivaroxaban. We assessed the cost of ABI screening at $100 per patient and added additional costs for physician visits ($100) and cost of rivaroxaban ($470). We used a 30-day cycle and performed analysis over 30 years. We evaluated quality-adjusted life-years (QALYs) from previous studies and determined the incremental cost effectiveness ration (ICER) according to our model. We performed sensitivity analysis of variables with uncertainty and report them in a Tornado diagram showing the variables with the greatest effect on the ICER. Our model estimates screening with ABI costs $109,382 compared with $99,607 without screening (difference $9775). The QALYs gained from screening was 0.075 generating an ICER of 130,897/QALY. Factors affecting the ICER was the cost of rivaroxaban and the reduction in cardiovascular events with rivaroxaban (Figure). If rivaroxaban cost less than $100 per 30 days this would reduce the ICER to $31,000/QALY and would make PAD screening with the ABI cost effective. According to our model, screening patients with CAD for PAD to start low dose rivaroxaban is not currently cost effective due to the cost of medication. However, vascular surgeons vascular surgeons have a unique opportunity to prescribe or advocate for low dose rivaroxaban in patients with PAD to help improve cardiovascular outcomes.