Abstract

Warfarin, an anticoagulant commonly used to prevent and control blood clots, is complicated to use because the optimal dose varies greatly among patients. If the dose is too high, the risk of serious bleeding increases; if the dose is too low, the risk of stroke increases. We estimate the potential health benefits and resulting changes in healthcare costs should it become feasible to base personalized warfarin dosing decisions on appropriate genetic testing. Using different assumptions regarding the costs and effectiveness of genetic testing, we estimate that formally integrating genetic testing into routine warfarin therapy could allow American warfarin users to avoid 4500–22,000 serious bleeding events annually. Genetic-based therapy could also reduce the incidence of strokes among patients taking warfarin. We estimate that the additional cost per patient from integrating genetic testing into warfarin therapy could range from US$300 in our pessimistic case, to substantial healthcare cost savings in the optimistic case.