Development of a clinical prediction model for an international normalised ratio ≥ 4·5 in hospitalised patients using vitamin K antagonists

Albert R Dreijer*, Joseph S Biedermann, Jeroen Diepstraten, Anouk D Lindemans, Marieke J H A Kruip, Patricia M L A van den Bemt, Yvonne Vergouwe

*Corresponding author for this work

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Vitamin K antagonists (VKAs) used for the prevention and treatment of thromboembolic disease, increase the risk of bleeding complications. We developed and validated a model to predict the risk of an international normalised ratio (INR) ≥ 4·5 during a hospital stay. Adult patients admitted to a tertiary hospital and treated with VKAs between 2006 and 2010 were analysed. Bleeding risk was operationalised as an INR value ≥4·5. Multivariable logistic regression analysis was used to assess the association between potential predictors and an INR ≥ 4·5 and validated in an independent cohort of patients from the same hospital between 2011 and 2014. We identified 8996 admissions of patients treated with VKAs, of which 1507 (17%) involved an INR ≥ 4·5. The final model included the following predictors: gender, age, concomitant medication and several biochemical parameters. Temporal validation showed a c statistic of 0·71. We developed and validated a clinical prediction model for an INR ≥ 4·5 in VKA-treated patients admitted to our hospital. The model includes factors that are collected during routine care and are extractable from electronic patient records, enabling easy use of this model to predict an increased bleeding risk in clinical practice.

Original languageEnglish
Pages (from-to)102-110
Number of pages9
JournalBritish Journal of Haematology
Issue number1
Publication statusPublished - Apr-2018
Externally publishedYes


  • Age Factors
  • Aged
  • Aged, 80 and over
  • Anticoagulants/administration & dosage
  • Female
  • Humans
  • International Normalized Ratio
  • Length of Stay
  • Male
  • Middle Aged
  • Models, Cardiovascular
  • Sex Factors
  • Thromboembolism/blood
  • Vitamin K/antagonists & inhibitors

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