A retrospective nationwide register study to characterize and compare non-valvular atrial fibrillation (NVAF) patients in Norway treated with novel oral anticoagulants (NOACs) and warfarin on drug utilization patterns, discontinuation and bleeding complication rates (Beyond Study Norway)

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Drug utilisation

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Study drug International non-proprietary name (INN) or common name:
  APIXABAN

  RIVAROXABAN

  DABIGATRAN

  WARFARIN

  PHENPROCOUMON
• Medical condition to be studied:
  Atrial fibrillation

Population studied

• Age groups:
  • Adults (18 to < 46 years)
  • Adults (46 to < 65 years)
  • Adults (65 to < 75 years)
  • Adults (75 to < 85 years)
  • Adults (85 years and over)
• Special population of interest:
  Renal impaired

  Hepatic impaired

  Immunocompromised

  Pregnant women
• Estimated number of subjects:
  72000

Study design details

• Main study objective:
  Primary objective is to describe and compare the clinical and patient characteristics such as CHADS2, CHA2DS2-VASc and HAS-BLED score, previous OAC use, bleeding history, concomitant medications and co-morbidities of all NVAF patients who initiated an OAC in the study period, overall and separately by each OAC (apixaban, dabigatran, rivaroxaban, warfarin), by OAC-switch status and previous OAC use
• Outcomes:
  Primary objective is to describe and compare the clinical and patient characteristics such as CHADS2, CHA2DS2-VASc and HAS-BLED score, previous OAC use, bleeding history, concomitant medications and co-morbidities of all NVAF patients who initiated an OAC in the study period, overall and separately by each OAC (apixaban, dabigatran, rivaroxaban, warfarin), by OAC-switch status and previous OAC use, To determine predictive factors of patients initiating each OAC as monotherapy (without a switch from a different OAC).To identify predictive factors of switching.To identify predictive factors of discontinuation.To compare clinically relevant bleedings and major bleeding rates for NVAF patients treated with OAC therapy.
• Data analysis plan:
  Patient characteristics for each OAC group will be described by the mean, standard deviation, median, first and third quartiles, and minimum and maximum for continuous variables, and by the number and percentage of patients in each category for categorical variables. Regression analysis will be the primary analytical approach with both unadjusted and adjusted models to be estimated and patient characteristics, OAC group, previous OAC use, co-morbidities, concomitant medications measured at baseline as candidate independent variables. Predictive performance of the final models will be assessed by the c-statistic. For time to event analyses our primary approach will be Cox proportional hazard regression analysis with the same candidate independent variables as above. A propensity score matching approach will also be considered as an analysis option.