Can We Predict Daily Adherence to Warfarin? Results From the International Normalized Ratio Adherence and Genetics (IN-RANGE) Study
ABSTRACT Warfarin is the primary therapy to prevent stroke and venous thromboembolism. Significant periods of nonadherence frequently go unreported by patients and undetected by providers. Currently, no comprehensive screening tool exists to help providers assess the risk of nonadherence at the time of initiation of warfarin therapy.
This article reports on a prospective cohort study of adults initiating warfarin therapy at two anticoagulation clinics (university- and Veterans Affairs-affiliated). Nonadherence, defined by failure to record a correct daily pill bottle opening, was measured daily by electronic pill cap monitoring. A multivariable logistic regression model was used to develop a point system to predict daily nonadherence to warfarin.
We followed 114 subjects for a median of 141 days. Median nonadherence of the participants was 14.4% (interquartile range [IQR], 5.8-33.8). A point system, based on nine demographic, clinical, and psychosocial factors, distinguished those demonstrating low vs high levels of nonadherence: four points or fewer, median nonadherence 5.8% (IQR, 2.3-14.1); five points, 9.1% (IQR, 5.9-28.6); six points, 14.5% (IQR, 7.1-24.1); seven points, 14.7% (IQR, 7.0-34.7); and eight points or more, 29.3% (IQR, 15.5-41.9). The model produces a c-statistic of 0.66 (95% CI, 0.61-0.71), suggesting modest discriminating ability to predict day-level warfarin nonadherence.
Poor adherence to warfarin is common. A screening tool based on nine demographic, clinical, and psychosocial factors, if further validated in other patient populations, may help to identify groups of patients at lower risk for nonadherence so that intensified efforts at increased monitoring and intervention can be focused on higher-risk patients.
Full-textDOI: · Available from: Maureen Price, Jun 01, 2015
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ABSTRACT: Background Depressive symptoms have detrimental effects on quality of life and mortality. Poor adherence to treatment regimen is a potential mechanism for the increased risk for adverse medical events associated with depression. Regarding oral anticoagulation with vitamin K antagonists, adherence is crucial for the outcome. Little is known about the clinical relevance of current depressiveness for anticoagulation treatment.Objectives To examine the impact of current depressiveness on anticoagulation treatment in regular medical care.Patients/Methods We examined the association between clinically significant depressiveness as assessed by the Patient Health Questionnaire-2 ≥ 2 (PHQ-2 ≥ 2) with the percentage of time in the therapeutic range (TTR), self-rated compliance, several aspects of health literacy, anticoagulation side-effects and treatment satisfaction in a cross-sectional study of 1,790 oral anticoagulation outpatients.Results716 participants (40.0%) had clinically significant depressive symptoms. Depressed persons reported lower compliance with intake of prescribed medication and regular visits for control of anticoagulation, more unspecific side-effects (e.g. pruritus) and lower satisfaction with the anticoagulation treatment and their doctors’ expertise and empathy. Depressed as compared with non-depressed individuals had a lower TTR (-4.67, 95%CI -8.39 to -0.95). Increasing severity of depressiveness was related with decreasing TTR. However, depressiveness lost its significant impact on TTR after multivariable adjustment (-3.11, 95%CI -6.88 to 0.66).Conclusions Clinically significant depressiveness was highly prevalent and impaired several aspects of anticoagulation treatment. Depressiveness should be regarded as a clinically significant condition that needs to be addressed in the management of anticoagulation patients.This article is protected by copyright. All rights reserved.Journal of Thrombosis and Haemostasis 10/2014; 12(12). DOI:10.1111/jth.12743 · 5.55 Impact Factor
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ABSTRACT: Stroke prevention in atrial fibrillation (SPAF) has traditionally been confined to aspirin and warfarin therapy. Based on CHADS2 scoring it was clearly delineated when aspirin and warfarin would be used in individual patients, but many patients had to forgo recommended therapy due to contraindications or adverse events. There has recently been a paradigm shift in SPAF, with new and promising options on the horizon. These emerging strategies include dual antiplatelet therapy, direct thrombin inhibition, factor Xa inhibition and mechanical prophylaxis therapy. With each of these aforementioned approaches there are moderate to large clinical trials that assess the comparative effectiveness of these approaches in direct comparative trials. From an Ovid MEDLINE search from 1950 to present, we systematically identified 15 randomized trials comparing two thromboprophylactic drugs, devices or procedures for SPAF. Specific mechanical, pharmacologic and pharmacokinetic advantages and disadvantages are also reviewed.05/2012; 1(3):225-39. DOI:10.2217/cer.12.21
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ABSTRACT: Among long-term care (LTC) residents with atrial fibrillation (AF), the use of warfarin to prevent stroke has been shown to be suboptimal. For those who begin warfarin prophylaxis in LTC, persistence on this therapy has not been reported. This study was conducted to estimate persistence on warfarin among LTC residents with AF. A retrospective analysis was conducted by using data from an LTC database. Pharmacy dispensing data were used to track warfarin use in residents with a diagnosis of AF who were newly started on warfarin therapy. The main outcome measure was persistence of warfarin over the first year of therapy. Survival analysis included Kaplan-Meier plots and a multivariate Cox proportional hazards model to test the association of resident characteristics and conditions with warfarin discontinuation. A total of 148 residents new to warfarin therapy met all study inclusion criteria. Median age was 84 years; 69% were female. Median time to therapy discontinuation was 197 days (95% CI, 137-249) across all study residents. By 90 days after the initiation of therapy, 37% (95% CI, 28-47) of study residents had discontinued warfarin; by 1 year, 65% (54%-76%) had discontinued warfarin therapy. The multivariate Cox regression analysis found that the following factors were independently associated with discontinuation of warfarin therapy: age 65 to 74 years (hazard ratio [HR] = 3.01 [95% CI, 1.04-8.73]), female sex (HR = 0.45 [95% CI, 0.24-0.87]), Hispanic race/ethnicity (HR = 2.86 [95% CI, 1.30-6.26]), Midwest region (HR = 2.13 [95% CI, 1.02-4.48]), and Alzheimer disease or dementia (HR = 1.97 [95% CI, 1.05-3.68]). Although clinical practice guidelines exist for the prevention of stroke in AF patients, persistence on warfarin therapy seems suboptimal in many LTC residents with AF.Clinical Therapeutics 10/2013; 35(11). DOI:10.1016/j.clinthera.2013.09.010 · 2.59 Impact Factor