Simple Warfarin Dosing Algorithm Study
Warfarin is a blood thinner with a variable effect and requires regular blood monitoring and dose adjustments. Some family practices do not have the facilities or funding to use commercial tools than can assist with stabilizing the effect of warfarin. The investigators will test whether a simple and cost-free dosing tool can help these practices to improve warfarin management.
If this simple tool improves warfarin management, it will be freely available for practices in Canada and around the world. This will help physicians who have no access to more costly and/or complicated tools improve their warfarin dosing practice in a systematic fashion, and thereby maximize the health benefit of warfarin.
Warfarin reduces the risk of thromboembolism, but requires regular blood monitoring to keep the international normalized ration (INR) within a narrow therapeutic range to achieve maximum benefits. A low proportion of time spent within the therapeutic INR range, (TTR) is associated with reduced warfarin efficacy and potentially harmful results. To optimize TTR, international guidelines recommend the use of systematic evidence-based dosing methods (anticoagulation clinic, computerized systems, manual algorithm and patient self-management). A survey in the Hamilton area revealed that half of family physicians manage warfarin dosing without assistance from an evidence-based method. The simple manual dosing algorithm is a simple tool that helped increase the TTR at the Hamilton General Hospital's anticoagulant clinic to an excellent 73% among patients with target INR range 2-3. We will test whether the simple dosing algorithm can help to improve warfarin dosing of family physicians who are not assisted by evidence-based methods. We will randomize family practices to either use the simple dosing algorithm or to manage warfarin dosing as usual, to test whether the simple dosing algorithm achieves a superior TTR.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Treatment
Caroline Medical Group
Population Health Research Institute
Results (where available)
- Source: http://clinicaltrials.gov/show/NCT01008215
- Information obtained from ClinicalTrials.gov on July 15, 2010
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Medical and Biotech [MESH] Definitions
An anticoagulant that acts by inhibiting the synthesis of vitamin K-dependent coagulation factors. Warfarin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, pulmonary embolism, and atrial fibrillation with embolization. It is also used as an adjunct in the prophylaxis of systemic embolism after myocardial infarction. Warfarin is also used as a rodenticide.
Measurable biological parameters that serve for drug development, safety and dosing (DRUG MONITORING).
A coumarin that is used as an anticoagulant. Its actions and uses are similar to those of WARFARIN. (From Martindale, The Extra Pharmacopoeia, 30th ed, p233)
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
A coumarin that is used as an anticoagulant. It has actions similar to those of WARFARIN. (From Martindale, The Extra Pharmacopoeia, 30th ed, p226)