Dabigatran Adherence Study
Atrial fibrillation is a common cardiac problem and it increases the risk of clotting events especially in patients with multiple clotting risk factors. Therefore, patients are treated with warfarin, an oral anti-coagulant, which requires frequent lab monitoring and dose adjustment. The majority of veterans on warfarin are managed in anti-coagulation clinics staffed by pharmacists who routinely contact patients to remind them to get blood draws, to re-enforce taking of their medication, and to adjust warfarin dose based on lab test values. Not having adequate anti-coagulation increases the risk of clotting and is most commonly due to not taking medications as prescribed.
Dabigatran is a newly approved medication that may be better for some patients than warfarin for lowering the risk of stroke and clotting in patients with atrial fibrillation. Additional advantages of dabigatran include fewer drug problems, and eliminating the need lab monitoring. However, following the doctors instructions for taking the medication is an important consideration with dabigatran because it is a twice a day medication and requires monthly refills, both of which are strong risk factors for not following the prescribed instructions. In addition, patients taking dabigatran will not be followed in anti-coagulation clinics because there is no lab value to monitor, and therefore, they will no longer benefit from the support provided by these clinics.
Rivaroxaban is a newly approved, Factor Xa inhibitor, oral medication prescribed to reduce the risk of stroke and systemic embolism among patients with atrial fibrillation. Rivaroxaban is a once daily medication that is recommended to be taken during an evening meal to reduce the potential risk of decreased efficacy of therapy. In a randomized, double-blind study comparing warfarin to Rivaroxaban, Rivaroxaban was found non-inferior to warfarin for the prevention of stroke and systemic embolism in patients with atrial fibrillation, and the risk of major and critically relevant non-major bleeding were similar between the two anticoagulants. In addition, patients taking Rivaroxaban will not be followed in anti-coagulation clinics because there is no lab value to monitor, and therefore, they will no longer benefit from the adherence support provided by these clinics. Non-adherence to chronic cardiovascular medications is common and non-adherence to Rivaroxaban may potentially limit its effectiveness in routine clinical use.
Apixaban is a FDA approved anticoagulant, Factor Xa inhibitor, oral medication prescribed to reduce the risk of stroke and blood clots among patients with atrial fibrillation. Apixaban is taken twice daily. In a double-blind, double-dummy, randomized, non-inferior and superior controlled trial, apixaban was found to be superior to warfarin in reducing stroke, systemic embolism, and death. In addition, patients taking apixaban will not be followed in anti-coagulation clinics because there is no lab value to monitor, and therefore, they will no longer benefit from the adherence support provided by these clinics. Non-adherence to chronic cardiovascular medications is common and non-adherence to apixaban may potentially limit its effectiveness in routine clinical use.
It is anticipated that many patients will be switched to dabigatran, Rivaroxaban, or Apixaban following recent publication of criteria for dabigatran use from the VA National Pharmacy Benefits Management Program. This provides an opportune time to conduct the proposed study focusing on adherence to dabigatran, Rivaroxaban, and Apixaban. We will first perform qualitative interviews with patients (n~30) and pharmacists (n~20) to better understand barriers and facilitators to dabigatran adherence. Informed by the qualitative findings and the literature on interventions to improve cardiovascular medication adherence, we will develop and pilot test a multi-faceted intervention to improve adherence among patients recently started on dabigatran, Rivaroxaban, and Apixaban.
The Specific aims of this study are:
- Aim 1 - Conduct interviews with a sample of patients (n=30) recently started on dabigatran for atrial fibrillation to determine why patients take and don't take their medications.
- Aim 2 - Conduct interviews with pharmacists (n=20) in anti-coagulation clinics in order to understand their opinions why patients take and don't take their medications.
- Aim 3 - Informed by the interviews, develop and test an intervention targeting patients and pharmacists to improve adherence to dabigatran, rivaroxaban, and apixaban.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Health Services Research
|Official Title:||Pilot Intervention to Improve Dabigatran Adherence|
- Gaps between prescription refills for dabigatran [ Time Frame: 9 months ] [ Designated as safety issue: No ]The investigators will calculate the # of gap days between refills for dabigatran/rivaroxaban/apixaban for each 6 months of the pilot intervention. This will be based on pharmacy refill data and calculated using the date dabigatran/rivaroxaban/apixaban was dispensed and the # of days supplied for that prescription. We will add the # of gap days for each 6 months of the pilot for each patient, and compare the total # of gaps days between intervention and usual care patients. The gap days between refills is a validated measure of adherence and identifies patients with sub-optimal adherence.
|Study Start Date:||January 2012|
|Estimated Study Completion Date:||June 2014|
|Estimated Primary Completion Date:||June 2014 (Final data collection date for primary outcome measure)|
Experimental: Facilitator to Dabigatran Adherence
Placebo Comparator: Arm 2
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|United States, Colorado|
|VA Eastern Colorado Health Care System, Denver|
|Denver, Colorado, United States, 80220|
|Principal Investigator:||Michael Ho, MD PhD||VA Eastern Colorado Health Care System, Denver|