Is home monitoring of international normalised ratio safer than clinic-based monitoring?

Abstract

A best evidence topic was written according to a structured protocol, to answer the question: 'In patients taking warfarin, is home self-monitoring of international normalized ratio (INR) safer than clinic-based testing in reducing bleeding, thrombotic events and death?' Altogether, 268 papers were found using the reported search. Five papers represented the highest level of evidence to answer the clinical question (four systematic reviews with meta-analysis and one meta-analysis). The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The principal outcomes of interest were death, major haemorrhage, major thromboembolism, and time (or percentage time) spent within the therapeutic range, compared between self-monitoring/self-management and conventional management. Self-monitoring/self-management was associated with a significantly reduced risk of all-cause mortality of 26-42%. All meta-analyses reported on major thromboembolism, finding significant reductions in risk of ~50%. One meta-analysis found a 35% reduction in the risk of major haemorrhage, with the other four studies finding no significant difference. Only one study found self-monitoring/self-management to be associated with a significantly greater proportion of time within range, with another finding no significant difference in either the percentage of therapeutic results or in the time within range. The remaining two could not combine data for meta-analysis owing to methodological heterogeneity. We conclude that self-monitoring/self-management appears to be safer than conventional management. It is associated with consistently lower rates of thromboembolism and may also be associated with reduced risk of bleeding and death. This supports the updated guidance from the American College of Chest Physicians, recommending self-management of INR for patients who are both competent and motivated.

Implementation of home-based international normalized ratio testing in adult patients treated with warfarin

“…Home INR testing has been shown to have favorable outcomes in the improvement of TTR. Statistically significant improvements in TTR were found in numerous studies and meta-analyses comparing home testing to clinic-based testing (Cumberworth, Mabvuure, Hallam, & Hindocha, 2013; Heneghan et al, 2016; Matchar et al, 2010; Xu et al, 2012). Even when home-testing patients returned to clinic-based care, they continued to show statistically significant improvements in their TTR compared with the control group (75% vs. 59%, respectively) (Ryan, O'Shea, & Byrne, 2010).…”

“…Improvements in TTR translate into a reduction in adverse events, leading to cost savings and improvements in patient well-being (Lafata, Martin, Kaatz, & Ward, 2000; Phibbs et al, 2016). Home testing has been shown to significantly reduce thromboembolic events (42–55% reduction) and reduce all-cause mortality by 26–42% (Cumberworth et al, 2013). The reduction in major thromboembolism and mortality was confirmed by Bloomfield et al (2011).…”

Novel Anticoagulants in Atrial Fibrillation: Monitoring, Reversal and Perioperative Management

“…The target INR that is required in AF patients is between 2 and 3. Home monitoring of INR has proven to reduce the risk of thromboembolism, bleeding event, and death [ 10 ].…”

The Clinical Impact of Different Coagulometers on Patient Outcomes

“…Two options of self-care are available to the patient: patient self-testing (PST), where the INR test is executed by the patient and the INR value is communicated with the patient’s clinic, which responds with a new dosage schedule; and patient self-management (PSM), where the patients are trained to monitor and interpret the INR themselves, and adjust the anticoagulant dose accordingly. Systematic reviews have shown PST and PSM to be superior to standard monitoring, with fewer thromboembolic events, decreased overall mortality and reduced bleeding events [ 7 , 9 – 12 ]. PST/PSM is therefore recommended in anticoagulant guidelines for suitable patients [ 13 , 14 ].…”