Self-monitoring of oral anticoagulation: systematic review and meta-analysis of individual patient data.

BACKGROUND: Uptake of self-testing and self-management of oral anticoagulation [corrected] has remained inconsistent, despite good evidence of their effectiveness. To clarify the value of self-monitoring of oral anticoagulation, we did a meta-analysis of individual patient data addressing several important gaps in the evidence, including an estimate of the effect on time to death, first major haemorrhage, and thromboembolism. METHODS: We searched Ovid versions of Embase (1980-2009) and Medline (1966-2009), limiting searches to randomised trials with a maximally sensitive strategy. We approached all authors of included trials and requested individual patient data: primary outcomes were time to death, first major haemorrhage, and first thromboembolic event. We did prespecified subgroup analyses according to age, type of control-group care (anticoagulation-clinic care vs primary care), self-testing alone versus self-management, and sex. We analysed patients with mechanical heart valves or atrial fibrillation separately. We used a random-effect model method to calculate pooled hazard ratios and did tests for interaction and heterogeneity, and calculated a time-specific number needed to treat. FINDINGS: Of 1357 abstracts, we included 11 trials with data for 6417 participants and 12,800 person-years of follow-up. We reported a significant reduction in thromboembolic events in the self-monitoring group (hazard ratio 0·51; 95% CI 0·31-0·85) but not for major haemorrhagic events (0·88, 0·74-1·06) or death (0·82, 0·62-1·09). Participants younger than 55 years showed a striking reduction in thrombotic events (hazard ratio 0·33, 95% CI 0·17-0·66), as did participants with mechanical heart valve (0·52, 0·35-0·77). Analysis of major outcomes in the very elderly (age ≥85 years, n=99) showed no significant adverse effects of the intervention for all outcomes. INTERPRETATION: Our analysis showed that self-monitoring and self-management of oral coagulation is a safe option for suitable patients of all ages. Patients should also be offered the option to self-manage their disease with suitable health-care support as back-up. FUNDING: UK National Institute for Health Research (NIHR) Technology Assessment Programme, UK NIHR National School for Primary Care Research.

An evaluation of patient self-testing competency of prothrombin time for managing anticoagulation: pre-randomization results of VA Cooperative Study #481--The Home INR Study (THINRS).

Prior studies suggest patient self-testing (PST) of prothrombin time (PT) can improve the quality of anticoagulation (AC) and reduce complications (e.g., bleeding and thromboembolic events). "The Home INR Study" (THINRS) compared AC management with frequent PST using a home monitoring device to high-quality AC management (HQACM) with clinic-based monitoring on major health outcomes. A key clinical and policy question is whether and which patients can successfully use such devices. We report the results of Part 1 of THINRS in which patients and caregivers were evaluated for their ability to perform PST. Study-eligible patients (n = 3643) were trained to use the home monitoring device and evaluated after 2-4 weeks for PST competency. Information about demographics, medical history, warfarin use, medications, plus measures of numeracy, literacy, cognition, dexterity, and satisfaction with AC were collected. Approximately 80% (2931 of 3643) of patients trained on PST demonstrated competency; of these, 8% (238) required caregiver assistance. Testers who were not competent to perform PST had higher numbers of practice attempts, higher cuvette wastage, and were less able to perform a fingerstick or obtain blood for the cuvette in a timely fashion. Factors associated with failure to pass PST training included increased age, previous stroke history, poor cognition, and poor manual dexterity. A majority of patients were able to perform PST. Successful home monitoring of PT with a PST device required adequate levels of cognition and manual dexterity. Training a caregiver modestly increased the proportion of patients who can perform PST.

The impact of patient self-testing of prothrombin time for managing anticoagulation: rationale and design of VA Cooperative Study #481--the Home INR Study (THINRS).

BACKGROUND: Anticoagulation (AC) with warfarin reduces the risk of thromboembolism (TE) in a variety of applications, yet despite compelling evidence of the value and importance of high quality AC, warfarin remains underused, and dosing is often suboptimal. Approaches to improve AC quality include (1) an AC service (ACS), which allows the physician to delegate day-to-day details of AC management to another provider dedicated to AC care, and (2) incorporating into the treatment plan patient self-testing (PST) under which, after completing a training program, patients perform their own blood testing (typically, using a finger-stick blood analyzer), have dosage adjustments guided by a standard protocol, and forward test results, dosing and other information to the provider. Studies have suggested that PST can improve the quality of AC and perhaps lower TE and bleed rates. The purpose of Department of Veterans Affairs (VA) Cooperative Studies Program (CSP) #481, "The Home INR Study" (THINRS) is to compare AC management with frequent PST using a home monitoring device to high quality AC management (HQACM) implemented by an ACS with conventional monitoring of prothrombin time by international normalized ratio (INR) on major health outcomes. PST in THINRS involves use of an INR monitoring device that is FDA approved for home use. STUDY DESIGN: Sites are VA Medical Centers where the ACS has an active roster of more than 400 patients. THINRS includes patients with atrial fibrillation (AF) and/or mechanical heart valve (MHV) expected to be anticoagulated indefinitely. THINRS has two parts. In Part 1, candidates for PST are evaluated for 2 to 4 weeks for their ability to use home monitoring devices. In Part 2, individuals capable of performing PST are randomized to (1) HQACM with testing every 4 weeks and as indicated for out of range values, medication/clinical changes, or (2) PST with testing every week and as indicated for out of range values, medication/clinical changes. The primary outcome measure is event rates, defined as the percent of patients who have a stroke, major bleed, or die. Secondary outcomes include total time in range (TTR), other events (myocardial infarction (MI), non-stroke TE, minor bleeds), competence and compliance with PST, satisfaction with AC, AC associated quality of life (QOL), and cost-effectiveness. To assess the effect of PST frequency on TTR and other outcomes, at selected sites patients randomized to perform PST are assigned one of three test frequencies (weekly, twice weekly, or once every four weeks).