Predictors of anticoagulation quality in 15834 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

Christian Schaefer, Walter A. Wuillemin, Alfons Kessels, Alan Jacobson, Michael Nagler*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


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=15834; median age 72years; 301% 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 19; 95% confidence interval [CI] 18-20), long intervals between measurements (>14d; 15; 95% CI 13-17), female sex (OR 13; 95% CI 12-14), and management other than PSM (OR 14; 95% CI 12-16). At a threshold of 02 (at least one variable present), the model predicted poor anticoagulation control with a sensitivity of 853% (95% CI: 840, 864) and a specificity of 285% (276, 295). The area under the receiver operated characteristic curve was 065. 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.
Original languageEnglish
Pages (from-to)677-685
JournalBritish Journal of Haematology
Issue number4
Publication statusPublished - Nov 2016


  • vitamin K antagonists
  • inhibitors
  • self care
  • International Normalized Ratio
  • anticoagulant administration
  • dosage
  • drug monitoring

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