Genetic testing not cost-effective in guiding initial dosing of blood-thinner warfarin
A wide range of factors-including variables related to health care and job characteristics-affect the risk of long-term disability for workers with back injuries, reports a study in the December 1 issue of Spine. In combination, the risk factors can predict the risk of chronic disability after back injury, and may help in targeting workers for
Full Post: Risk factors for chronic disability after back injury
New analyses led by the University of Cincinnati (UC) show that genetic testing used to guide initial dosing of the blood-thinner warfarin may not be cost-effective for typical patients with atrial fibrillation but may be for patients at higher risk for major bleeding.
This study is being published in the Jan. 20, 2009, edition of Annals of Internal Medicine .
Warfarin is commonly prescribed to prevent blood clotting, particularly for patients with atrial fibrillation-a type of abnormal heart rhythm.
Mark Eckman, MD, professor of medicine at UC and lead investigator of the study, says the U.S. Food and Drug Administration changed the labeling for warfarin in 2007, suggesting that clinicians consider genetic testing before initiating therapy.
“There are certain genes that are known to contribute to an increased sensitivity to warfarin,” he says. “The idea behind genetic testing-also known as pharmacogenetic-guided dosing- is to help guide the initial, and possibly lower, dose of warfarin for patients found to possess certain variants of the genes cytochrome P450 CYP2C9 and vitamin K epoxide reductase, or VKORC1. The hope is that more accurate dosing will translate into decreased major bleeds during the initiation phase of warfarin dosing, which is the first month or so.”
Eckman says the study looked at whether the benefit of testing is worth the costs associated with it.
Researchers first performed an analysis combining the results of the only three clinical studies published to date to determine the degree to which pharmacogenetic-guided dosing decreases the risk of major bleeds when compared with standard induction of treatment with warfarin.
The team next constructed a model to estimate the cost-effectiveness of a genotype-guided dosing strategy.
While they found that genotype-guided dosing resulted in better outcomes, it was at a relatively high cost-over $170,000 per quality-adjusted life year gained.
In other analyses, where they took into consideration the limitations of the studies, researchers found that there is only a 10 percent chance that genotype-guided dosing is likely to be cost-effective.
Researchers also looked at the impact of other variables on the cost-effectiveness of genotype-guided dosing.
Eckman says results show that genotype-guided dosing might be worth the costs if it:
- Is used for patients at high risk for hemorrhage
- Prevents more than 32 percent of major bleeding events
- Is available within 24 hours
- Costs less than $200
“This could be accomplished if testing were done in-house, at lower cost and without delays,” he says, noting that currently in most cases these tests need to be sent to outside laboratories which can lead to delays in starting treatment and increased cost. “Furthermore, future studies, such as the recently funded National Institutes of Health COAG trial, need to examine the impact of pharmacogenetic-guided dosing on bleeding risk and monitor outcomes long enough to determine the true duration of benefit.”
Eckman also suggests that rather than excluding patients at higher risk for bleeding, studies should offer enrollment if it has already been determined that these patients require warfarin.
“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.”
Patients who report receiving written and verbal instructions on the proper way to take the blood thinner warfarin are significantly less likely to suffer the serious gastrointestinal and brain bleeding problems that are associated with misuse of the drug, according to new research from the University of Pennsylvania School of Medicine. The study, published
Full Post: Improved communication about medications reduces complications among patients using common blood thinner
Back pain affects more than 80 percent of people and costs more than $100 billion annually in the U.S. But is the surgery cost effective? A study by researchers at Rush University Medical Center suggests that for patients with spinal stenosis, a laminectomy, or surgical removal of some soft bone and tissue, is a reasonable
Full Post: Cost effectiveness of spinal surgery examined
A cost-effectiveness analysis conducted by researchers at Stanford University Hospital in Calif., shows that an initial double-balloon enteroscopy (DBE) is a cost-effective approach for patients with obscure gastrointestinal (GI) bleeding. However, capsule-directed DBE (which is when the findings from an initial small bowel capsule endoscopy exam are used to guide the DBE procedure) may be
Full Post: Double-balloon enteroscopy offers cost-effective approach for obscure GI bleeding
Daiichi Sankyo Company, Limited, has announced that it has initiated its pivotal Phase III trial for DU-176b, an investigational oral Factor Xa inhibitor, in patients with atrial fibrillation. DU-176b is being developed solely by Daiichi Sankyo. The Phase III global study, Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation (ENGAGE-AF TIMI 48),
Full Post: Daiichi Sankyo starts trial of investigational factor Xa inhibitor for atrial fibrillation
Screening for a panel of gene variants associated with the risk for type 2 diabetes can identify adults at risk for the disorder but is not significantly better than assessment based on traditional risk factors such as weight, blood pressure and blood sugar levels. A multi-institutional research team, led by a Massachusetts General Hospital (MGH)
Full Post: Genetic screening no better than traditional risk factors for predicting type 2 diabetes