Is Genetic Testing for Warfarin Cost-Effective?

February 6, 2009

Genetic testing to guide initial dosing of warfarin is useful but unlikely to be cost-effective for persons with nonvalvular atrial fibrillation, according to a study published in the January 20 issue of the Annals of Internal Medicine. Principal investigator Mark H. Eckman, MD, MS, professor of medicine at the University of Cincinnati, noted that in 2007, the FDA changed the labeling for warfarin, suggesting that clinicians consider genetic testing before initiating therapy. Eckman led a team of researchers to determine whether genetic testing-also known as pharmacogenetic-guided dosing and genotype-guided dosing-is worth the cost. The team combined the results of the only 3 published clinical studies to analyze the extent to which pharmacogenetic-guided dosing decreases the risk of hemorrhage compared with standard induction of warfarin therapy.

Genetic testing to guide initial dosing of warfarin is useful but unlikely to be cost-effective for persons with nonvalvular atrial fibrillation, according to a study published in the January 20 issue of the Annals of Internal Medicine. Principal investigator Mark H. Eckman, MD, MS, professor of medicine at the University of Cincinnati, noted that in 2007, the FDA changed the labeling for warfarin, suggesting that clinicians consider genetic testing before initiating therapy. Eckman led a team of researchers to determine whether genetic testing-also known as pharmacogenetic-guided dosing and genotype-guided dosing-is worth the cost. The team combined the results of the only 3 published clinical studies to analyze the extent to which pharmacogenetic-guided dosing decreases the risk of hemorrhage compared with standard induction of warfarin therapy.

The researchers found that pharmacogenetic-guided dosing resulted in better outcomes, but at a relatively high cost: more than $170,000 per quality-adjusted life-year (QALY). On the basis of current data and cost of testing (approximately $400), there is only a 10% chance that pharmacogenetic-guided dosing is likely to be cost-effective (eg, less than $50,000 per QALY). Sensitivity analyses showed that for genetic testing to cost less than $50,000 per QALY, it would have to either be restricted to persons at high risk for hemorrhage or meet the following criteria: prevent more than 32% of major bleeding events, be available within 24 hours, and cost less than $200.

“This could be accomplished if testing were done in-house, at lower cost, and without delays,” Eckman said. “Personalized, predictive medicine offers great promise, but we need to carefully examine the benefits and understand the cost-effectiveness of such strategies before we spend a lot of money on very expensive tests.”

Psoriasis Patients Benefit From Online Support
Online support communities are a valuable educational resource and offer psychological and social support for persons with psoriasis. Researchers led by Joseph C. Kvedar, MD, founder and director of the Center for Connected Health, Boston, and vice chair of the department of dermatology, Harvard Medical School, Boston, conducted a Web-based, cross-sectional survey of 260 persons from 5 online psoriasis support groups between October 2006 and January 2007. Nearly three-fourths (73.7%) of study participants (average age, 40 years) reported having moderate or more severe psoriasis, and about four-fifths (79.9%) rated their general health as average or better. Most participants were college-educated (84.3%) and white (75.7%); 60.4% were women.

Findings of the study, published in the January issue of the Archives of Dermatology, indicated that the primary factors in the use of an online support site were availability of resources (95.3%), convenience (94%), access to good advice (91%), and lack of embarrassment when dealing with personal issues (90.8%). Almost two-thirds (65.7%) of participants reported that online support gave them a sense of control over their psoriasis. The most common online activities were posting messages (65%) and searching for information (63.1%).

Nearly half of participants perceived improvements in their quality of life (QOL) and psoriasis condition (49.5% and 41%, respectively) since joining a site. Intensity of participation in online support activities was associated with improved QOL (P = .002) but not with improvements in psoriasis. “Although online psoriasis support groups are still in their nascent stage, they have captured a loyal and growing audience. The dermatology community should consider leveraging the infrastructure of online support groups to build on delivering personalized and integrated medical care to individuals affected by psoriasis,” the authors concluded.