Is home warfarin self-management effective? Results of the randomised Self-Management of Anticoagulation Research Trial

Abstract

AimsThe Warfarin Self-Management Anticoagulation Research Trial (Warfarin SMART) was designed to determine whether patients self-managing warfarin (PSM) using the CoaguChek device and a dosing algorithm developed for the trial could keep the INR (International Normalised Ratio) test in target range at least as often as patients managed by usual care by the family doctor or hospital clinic. Methods and Results310 patients were randomly assigned to PSM or usual care. The PSM group was trained to perform home INR testing and warfarin dosing using a validated ColourChart algorithm. The primary endpoint was the proportion of times over 12 months that a monthly, blinded "outcome INR test", measured in a central laboratory, was outside the patients' target therapeutic range.The rate of out-of-range outcome INRs was lower in PSM, and non-inferior to the usual care group (PSM: 36% vs. usual care: 41%, P<0.0001 for non-inferiority; P=0.08 for superiority in closed-loop testing). The deviations from the patients' midpoint of target INR range (P=0.02) and number of extreme INRs (P=0.03) were significantly less in the PSM group than the usual-care group. There was no significant difference between groups in rates of bleeding or thrombotic adverse events. ConclusionPatient self-management performed at least as well as usual care in maintaining the INR within the target range, without any safety concerns. This treatment modality for the long-term use of warfarin has the potential to change current local and international practice.Warfarin SMART 8-Jul-13 3

National Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand: Australian Clinical Guidelines for the Diagnosis and Management of Atrial Fibrillation 2018

“…In addition, the mobility of point-of-care testing enables multidisciplinary management of patients and improves continuity of care. In Australia, practitioner-led point-of-care INR testing for the management of patients with AF has been trialled in general practices [271,272], outpatient clinics [273], aged-care facilities [274], and community pharmacies [275,276], as well as in conjunction with home-based medicine review services led by accredited pharmacists [277], across metropolitan or urban, [271,273,274,[277][278][279], rural [271,272,276,277], and remote [271,277] Resources and other considerations: In general, point-ofcare devices (and consumables such as testing strips) are currently relatively expensive to purchase (in the absence of Medicare rebates). Overall, they are generally cost effective in terms of optimising related health outcomes [280]; however, this depends on the overall model of care in which the devices are used [281].…”

International normalized ratio self-testing and self-management: improving patient outcomes

“…Fourteen trials included patients on oral anticoagulant treatment for any indication. 6 – 19 Four trials considered only patients on lifelong oral anticoagulation after heart valve replacement with a mechanical prosthesis. 20 – 23 Two trials included only patients on long-term anticoagulation for atrial fibrillation.…”

“…Baumann et al in the EMPoWarMENT study 26 have studied 28 wafarinized children performing self-testing for >3 months and randomized them to self-testing at home or self-management. The mean age was 10 years, 1 – 19 and 93% were followed during 12 months. Mean number INR test over the study was around 22 either for self-testing or self-management.…”

A prospective pilot study comparing nasal blood sampling and venipuncture for the assessment of hemoglobin levels and INR

“…More than a third of patients on vitamin K antagonists (VKA) are outside of the INR target range in the setting of epistaxis . Thus, it would seem that epistaxis is an apparent indicator of a possible overexposure to antithrombotic medication, and testing to confirm this suspicion should not be forgone.…”