Patterns of long-term use of non-vitamin K antagonist oral anticoagulants for non-valvular atrial fibrillation: Quebec observational study

Pharmacoepidemiol Drug Saf. 2017 Dec;26(12):1546-1554. doi: 10.1002/pds.4333. Epub 2017 Oct 6.

Abstract

Purpose: Studies on long-term utilization of non-vitamin K antagonist oral anticoagulants (NOACs) in non-valvular atrial fibrillation (NVAF) are scarce. We evaluated predictors of use and long-term persistence of NOACs in a real-world setting.

Methods: This population-based cohort study used the computerized databases of the Canadian Province of Quebec's health insurance. Patients with a first NVAF diagnosis from 2011 until 2014 were included. A logistic regression model yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for predictors of treatment initiation with NOACs versus VKAs. Cox proportional hazards models yielded adjusted hazard ratios (HRs) and 95% CIs for predictors of switching from VKAs to NOACs versus remaining on VKAs, and for predictors of discontinuation of anticoagulation treatment.

Results: Of the 62 867 newly diagnosed NVAF patients, 14 646 initiated NOACs and 17 685 VKAs. Initiation with NOACs was less likely for patients ≥ 80 years old (OR 0.55, 95% CI 0.41-0.73) or with CHA2 DS2 -VASc ≥ 2 (OR 0.49, 95% CI 0.42-0.57). Switching from VKAs to NOACs was less likely for patients with chronic kidney disease (HR 0.53, 95% CI 0.48-0.59). After 3 years, persistence was 54% with NOACs and 25% with VKAs. Discontinuation of anticoagulation treatment was less likely for patients ≥ 80 years old (HR 0.47, 95% CI 0.40-0.55) or with CHA2 DS2 -VASc ≥ 2 (HR 0.64, 95% CI 0.57-0.70).

Conclusions: Older, high-risk patients are less likely to initiate NOACs than VKAs. NOAC users show a higher long-term persistence than VKA users, and older, high-risk patients are less likely to discontinue anticoagulation treatment.

Keywords: drug utilization; pharmacoepidemiology; treatment persistence.

Publication types

  • Observational Study

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Aged, 80 and over
  • Anticoagulants / administration & dosage*
  • Anticoagulants / classification*
  • Atrial Fibrillation / complications*
  • Cohort Studies
  • Drug Administration Schedule
  • Female
  • Humans
  • Male
  • Middle Aged
  • Quebec / epidemiology
  • Risk Factors
  • Thrombosis / epidemiology
  • Thrombosis / prevention & control*
  • Vitamin K / administration & dosage*

Substances

  • Anticoagulants
  • Vitamin K