Accuracy of the point-of-care coagulometer CoaguChek XS in the hands of patients

Performance of the microINR Point-of-Care System Used by Self-Testing Patients: A Multicenter Clinical Trial

Introduction  Anticoagulation monitoring is a major practical and clinical challenge. We assessed the performance of the microINR system in patient self-testing (PST). Methods  This study was performed at four US medical centers. After the training visit of warfarin anticoagulated patients ( n  = 117) on microINR system, PST was performed at home and in two visits to the medical centers. At the medical centers, both PST and healthcare professionals (HCPs) performed duplicate tests with the microINR System. A venous blood sample for the laboratory testing was also extracted. Accuracy and precision were assessed. Results  The comparison between microINR PST results and microINR HCP results revealed an equivalence with a slope of 1.00 (95% confidence interval [CI]: 1.00-1.00), and an intercept of 0.00 (95% CI: 0.00-0.00). When compared with the laboratory analyzer, microINR PST results also showed good correlation with a slope of 0.94 (95% CI: 0.86-1.04) and an intercept of 0.14 (95% CI: -0.09-0.34). Predicted bias values at international normalized ratio (INR) 2.0, 3.5, and 4.5 were 0% against HCP and ≤2.5% against the laboratory. Analytical agreement with both HCP and laboratory was 100% according to ISO17593 and 99.1 and 100% according to CLSI POCT14 with HCP and laboratory, respectively. Clinical agreement with HCP regarding 2.0-4.0 as INR therapeutic range was 98% (within range). The precision (coefficient of variation) of microINR system used by PST was comparable to HCP. Conclusion  The microINR results when used by self-testing patients show satisfactory concordance to both HCP results and laboratory analyzer. The microINR system is adequate for self-testing use.

Management of Outpatient Warfarin Therapy amid COVID-19 Pandemic: A Practical Guide

Many healthcare resources have been and continue to be allocated to the management of patients with COVID-19. Therefore, the ongoing care of patients receiving oral anticoagulation with warfarin is likely to be compromised amid this unprecedented crisis. This article discusses a stepwise algorithm for the management of outpatient warfarin therapy. Alternative management strategies are presented and discussed, including alternative pharmacological therapy options and self-monitoring. Our algorithm aims to help clinicians safely optimize the treatment of patients requiring anticoagulation therapy in the context of the global response to the current pandemic.

Predictors of anticoagulation quality in 15 834 patients performing patient self-management of oral anticoagulation with vitamin K antagonists in real-life practice: a survey of the International Self-Monitoring Association of Orally Anticoagulated Patients

Although patient self-management (PSM) of oral anticoagulation with vitamin K antagonists is recommended for patients requiring long-term anticoagulation, important aspects are still unclear. Using data from a large international survey (n = 15 834; median age 72 years; 30·1% female), we studied predictors of poor anticoagulation control (percentage of International Normalized Ratio values within therapeutic range below 75%) and developed a simple prediction model. The following variables were identified as risk factors for poor anticoagulation control and included in the final model: higher intensity of therapeutic range (odds ratio [OR] on every level 1·9; 95% confidence interval [CI] 1·8-2·0), long intervals between measurements (>14 d; 1·5; 95% CI 1·3-1·7), female sex (OR 1·3; 95% CI 1·2-1·4), and management other than PSM (OR 1·4; 95% CI 1·2-1·6). At a threshold of 0·2 (at least one variable present), the model predicted poor anticoagulation control with a sensitivity of 85·3% (95% CI: 84·0, 86·4) and a specificity of 28·5% (27·6, 29·5). The area under the receiver operated characteristic curve was 0·65. Using the proposed prediction model, physicians will be able to identify patients with a low chance of performing well, considering additional training, regular follow-up, or adjustment of therapeutic ranges.

Patient self-management of oral anticoagulation with vitamin K antagonists in everyday practice: efficacy and safety in a nationwide long-term prospective cohort study

Patient self-management (PSM) of oral anticoagulation is under discussion, because evidence from real-life settings is missing. Using data from a nationwide, prospective cohort study in Switzerland, we assessed overall long-term efficacy and safety of PSM and examined subgroups. Data of 1140 patients (5818.9 patient-years) were analysed and no patient were lost to follow-up. Median follow-up was 4.3 years (range 0.2-12.8 years). Median age at the time of training was 54.2 years (range 18.2-85.2) and 34.6% were women. All-cause mortality was 1.4 per 100 patient-years (95% CI 1.1-1.7) with a higher rate in patients with atrial fibrillation (2.5; 1.6-3.7; p<0.001), patients>50 years of age (2.0; 1.6-2.6; p<0.001), and men (1.6; 1.2-2.1; p = 0.036). The rate of thromboembolic events was 0.4 (0.2-0.6) and independent from indications, sex and age. Major bleeding were observed in 1.1 (0.9-1.5) per 100 patient-years. Efficacy was comparable to standard care and new oral anticoagulants in a network meta-analysis. PSM of properly trained patients is effective and safe in a long-term real-life setting and robust across clinical subgroups. Adoption in various clinical settings, including those with limited access to medical care or rural areas is warranted.