Cost-effectiveness analysis of ankle-brachial index screening in patients with coronary artery disease to optimize medical management.

Introduction: Screening for peripheral artery disease (PAD) with the ankle-brachial index (ABI) test is currently not recommended in the general population; however, previous studies advocate screening in high-risk populations. Although providers may be hesitant to prescribe low-dose rivaroxaban to patients with coronary artery disease (CAD) alone, given the reduction in cardiovascular events and death associated with rivaroxaban, screening for PAD with the ABI test and accordingly prescribing rivaroxaban may provide additional benefits. We sought to describe the cost-effectiveness of screening for PAD in patients with CAD to optimize this high-risk populations' medical management.

Methods: We used a Markov model to evaluate the ABI test in patients with CAD. We assumed 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 charges for physician visits ($100) and rivaroxaban cost ($470 per month). We used a 30-day cycle and performed analysis over 35 years. We evaluated quality-adjusted life years (QALYs) from previous studies and determined the incremental cost-effectiveness ratio (ICER) according to our model. We performed a deterministic and probabilistic sensitivity analyses of variables with uncertainty and reported them in a Tornado diagram showing the variables with the greatest effect on the ICER.

Results: Our model estimates decision costs to screen or not screen at $94,953 and $82,553, respectively. The QALYs gained from screening was 0.060, generating an ICER of $207,491 per QALY. Factors most influential on the ICER were the reduction in all-cause mortality associated with rivaroxaban and the prohibitively high cost of rivaroxaban. If rivaroxaban cost less than $95 per month, this would make screening cost-effective based on a willingness to pay threshold of $50,000 per QALY.

Conclusions: According to our model, screening patients with CAD for PAD to start low-dose rivaroxaban is not currently cost-effective due to insufficient reduction in all-cause mortality and high medication costs. Nevertheless, vascular surgeons have a unique opportunity to prescribe or advocate for low-dose rivaroxaban in patients with PAD to improve cardiovascular outcomes.