Predictors of Not Initiating Anticoagulation After Incident Venous Thromboembolism: A Danish Nationwide Cohort Study

Am J Med. 2020 Apr;133(4):463-472.e5. doi: 10.1016/j.amjmed.2019.08.051. Epub 2019 Oct 10.


Purpose: The purpose of this study was to investigate potential predictors associated with not initiating anticoagulation after incident venous thromboembolism.

Methods: We linked Danish nationwide health registries to identify all patients with incident venous thromboembolism from 2003 through 2016. We defined treatment noninitiation as not claiming a prescription for an anticoagulant drug within 30 days after hospital discharge. To identify potential predictors of noninitiation, relative risks (RRs) with 95% confidence intervals (CIs) were calculated adjusting for other compliance-related factors.

Results: The study included 38,044 patients with incident venous thromboembolism (53.2% female and median age 66.1 years). Of these, 24.1% (n = 9294) were noninitiators. Demographic and condition-related factors that predicted noninitiation included: female sex (RR 1.30; 95% CI, 1.25-1.34), age <30 vs age >65 years (RR 1.18; 95% CI, 1.13-1.33), hospitalization 0-3 days vs >3 days (RR 1.96; 95% CI, 1.87-2.07), incident deep venous thrombosis (RR 1.91; 95% CI, 1.81-2.01), and unprovoked venous thromboembolism (RR 1.13; 95% CI, 1.08-1.17). Socioeconomic factors had less influence on risk of noninitiation. Individual chronic diseases predictive of noninitiation included congestive heart failure (RR 1.27; 95% CI, 1.17-1.37), ischemic heart disease (RR 1.20; 95% CI, 1.13-1.28), and liver disease (RR 1.60; 95% CI, 1.42-1.81).

Conclusion: Up to one-fourth of patients diagnosed with incident venous thromboembolism did not initiate anticoagulant treatment within 30 days after hospital discharge. Identification of clinical predictors of noninitiation may enable implementation of patient-tailored strategies to improve adherence and thereby potentially prevent venous thromboembolism morbidity, mortality, and recurrence.

Keywords: Adherence; Anticoagulation; Compliance; Treatment; Venous thromboembolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anticoagulants / therapeutic use*
  • Cohort Studies
  • Denmark / epidemiology
  • Female
  • Hospitalization
  • Humans
  • Incidence
  • Male
  • Medication Adherence*
  • Middle Aged
  • Risk Factors
  • Socioeconomic Factors
  • Venous Thromboembolism / drug therapy*
  • Venous Thromboembolism / epidemiology
  • Venous Thromboembolism / psychology


  • Anticoagulants