Economic evaluation of DOACs vs VKAs highlights the disparity between high-income countries versus those with lower economic status.

Blog entry written on: ‘Economic evaluation of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) for stroke prevention in patients with atrial fibrillation: a systematic review and meta-analysis’, (bmjebm-2020-111634)’.

Authors: Sitaporn Youngkong, Surakit Nathisuwan, Rini Noviyani, Bhavani Shankara Bagepally, Usa Chaikledkaew, Nathorn Chaiyakunapruk, Gareth J. McKay, Piyamitr Sritara, John Attia, Ammarin Thakkinstian.

In this era of health finance constraint, economic evaluation of health interventions including pharmacological interventions, has become an instrumental component in dictating whether the payers would include such drug in the reimbursement scheme. This will ultimately lead to a huge impact on patient’s access to those health interventions in a given healthcare system. A great example in this case is atrial fibrillation (AF) which is one of the most common cause of cardioembolic stroke, with a global average incidence of 596.2 cases/100,000 population. Complications of AF, particularly stroke, lead to astronomical loss of lives along with healthcare resources.

Our study is the first systematic review and meta-analysis of cost-effectiveness studies that includes all four commonly used direct-acting oral anticoagulants (DOACs) including dabigatran, rivaroxaban, apixaban and edoxaban. These agents have clear pharmacological advantages compared to the vitamin K anticoagulants (VKAs) in many aspects and all have been shown to work at least as good as VKAs and with more favorable safety profile. Practice guidelines from various professional societies recommend DOACs over VKAs for stroke prevention in patients with AF based on this reason.

There have been a large number of cost-effectiveness studies comparing DOACs versus VKAs. However, it is difficult to derive the conclusion due to the differences in methodology and the lack of universal parameter to compare the findings. Recently, the pooling of incremental net benefits (INBs) has been suggested as a possible way to summarize the economic value of an intervention. Based on this concept, our team attempted to performed systematic review and meta-analysis of cost-effectiveness studies comparing DOACs with VKAs, and assessed the impact of various factors that may influence the result of such evaluation.

Based on the findings from our study, DOACs, at their current pricing, are cost-effective only in high-income countries but not in upper middle-income countries (UMICs) due partly to the lower socioeconomic status and the small number of studies available. We also found that payer’s perspective may also influence the outcome of the economic evaluation. While economic evaluation may depend on a myriad of factors, three key pillars, beyond the magnitude of efficacy and safety, are always, present in such exercise including drug pricing, willingness to pay (an indirect reflection of economic status of a health system) and methodologies deployed. Policy makers and pharmaceutical companies should together consider potential pathways to increase access to these useful agents by considering the impact of socioeconomic status on the cost-effectiveness for UMICs and potentially low- and middle-income countries.

Several key questions remain: how would DOACs performed in low- and middle-income countries where willingness to pay is generally lower but the performance of VKAs may also be much poorer which may accentuate the magnitude of benefits of DOACs? and how would the availability of generic DOACs with lower price would change this cost-effectiveness equation?

For now, it seems clear that the cost-effectiveness of DOACs lies on the triangle of drug pricing, willingness to pay, and payer’s perspective.

Authors

Sitaporn Youngkong

Institution: Mahidol University Health Technology Assessment (MUHTA) Graduate Program, Mahidol University, Bangkok, Thailand, Social and Administrative Pharmacy Division, Department of Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand.