Common flaws exist in published cost-effectiveness models of pharmacologic stroke prevention in atrial fibrillation

Abstract

Objectives: Decision makers use models to assist in evaluating the cost-effectiveness of pharmacologic stroke prevention in atrial fibrillation (SPAF).

Study design and setting: We performed a search of databases through October 3, 2012 to identify pharmacologic SPAF cost-effectiveness models.

Results: Of 30 identified models, 28 included warfarin, but only 60% assessed the impact of warfarin control on conclusions. Aspirin, dual antiplatelet, and newer anticoagulants were included in 41%, 10%, and 63% of models, respectively. Models used similar structures but included varying health states and made varying assumptions. They rarely reported performing a literature search to identify anticoagulant-specific inputs and used similar and older sources. Sixteen models used a lone randomized trial to reflect the efficacy and safety of main comparisons. One-third of models claimed a societal perspective; however, none included indirect costs. Patients typically initiated anticoagulation in the sixth or seventh decade of life and are followed for their lifetimes. Almost 70% of incremental cost-effectiveness ratios were below reported willingness-to-pay thresholds. All used deterministic sensitivity analyses and 77% conducted Monte Carlo simulation. Less than half of the models were rated "high quality," yet were frequently published in high-impact journals.

Conclusion: Pharmacologic SPAF cost-effectiveness models have been extensively reported, but many may have flaws giving reason for decision makers to use caution. We provide 10 recommendations to avoid common flaws in SPAF cost-effectiveness models.

Keywords: Anticoagulants; Atrial fibrillation; Cost effectiveness; Decision modeling; Economics; Markov model; Medical.