Simple Warfarin Dosing Algorithm Study (KT-INR)
Can a simple and cost-free tool help family physicians to improve dosing of the blood thinner warfarin?
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.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Treatment
|Official Title:||Cluster Randomized Trial to Assess the Effect of Using a Simple Warfarin Maintenance Dosing Algorithm on the Quality of INR Control Among Canadian Family Practices|
- Mean time in therapeutic range for patients [ Time Frame: 1 Year ] [ Designated as safety issue: No ]
- Proportion of patients with TTR > 65% [ Time Frame: 1 Year ] [ Designated as safety issue: No ]
- Correlation between algorithm adherence and TTR [ Time Frame: 1 Year ] [ Designated as safety issue: No ]
- Among patients in both baseline and study sample: proportion of patients with TTR improvement [ Time Frame: 1 Year ] [ Designated as safety issue: No ]
|Study Start Date:||October 2009|
|Study Completion Date:||June 2011|
|Primary Completion Date:||April 2011 (Final data collection date for primary outcome measure)|
Algorithm (available in paper version and web-based version) will be used for warfarin maintenance dosing.
Warfarin Dosing algorithm (paper and electronic version)
No Intervention: Care as usual
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.
|Caroline Medical Group|
|Burlington, Ontario, Canada, L7R 4C7|
|Principal Investigator:||Stuart Connolly||McMaster University|