Warfarin-based genotyping not cost effective for most patients

Genotype-guided dosing of warfarin was not cost effective in patients with typical nonvalvular atrial fibrillation, but may be in patients at high risk for hemorrhage.

Researchers reviewed the results of three clinical studies that evaluated the degree to which pharmacogenetic-guided dosing of warfarin improved risk for major bleeding compared with standard induction treatment with warfarin.

The researchers determined that the cost-effectiveness of genotype testing, as measured in 2007 dollars, was more than $170,000 per quality–adjusted life–year. Based on the current cost of about $400 for such testing, the researchers concluded that there was only a 10% chance that genotype-guided dosing would be cost effective (less than $50,000 per quality–adjusted life–year).

They concluded that genetic testing would only be cost-effective if it was restricted to patients at high risk for hemorrhage, or if it could 1) prevent more than 32% of major bleeding events, 2) be available within 24 hours and 3) cost less than $200. – by Jason Harris

Ann Intern Med. 2009;150:73-83.

It is very important to recognize these results hinge on the assumption that the cost of the test is about $400. That is one thing we can almost guarantee will change for the better, rapidly. The cost of genetic testing has plummeted in just the past handful of years, and we will rapidly be at a point where such testing will cost less than $400, probably less than $100. On the surface of it, the message of this study is pessimistic: It costs too much to get better outcomes with genetic testing. The real lesson is optimistic: If we get testing to cost a reasonable amount, it looks like we've got a test that may be very much worth doing.

– James P. Evans, MD

Professor of Genetics and Medicine
University of North Carolina