Real-world Evidence of Prolonged Apixaban Treatment of Unprovoked Venous Thromboembolism

Study type

• Study topic:
  Human medicinal product

  Disease /health condition
• Study type:
  Non-interventional study
• Scope of the study:
  Drug utilisation
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Study drug International non-proprietary name (INN) or common name:
  APIXABAN
• Medical condition to be studied:
  Venous thrombosis

Population studied

• Short description of the study population:
  Patients were included in the study if they:; a) Had ≥1 medical claim with a primary or secondary unprovoked VTE diagnosis (index VTE event) in the inpatient or ambulatory setting during the identification period (01-Sep-2014 to 31-Dec-2017). The first VTE diagnosis will be identified as the index VTE event. If occurring in the outpatient setting, the index VTE event date will be defined as the service date; if in the inpatient setting, the discharge date will be designated as the index VTE event date. Qualifying outpatient encounters followed by a qualifying inpatient encounter within 7 days will be considered an inpatient episode (unless apixaban was initiated between encounters, in which case the event would be classified as an outpatient encounter);; b) Had ≥1 pharmacy claim for apixaban during the 30-day period following the index VTE event [during 01-Sep-2014-31-Dec-2016 or 6 months prior to study end so that all patients have the opportunity to have six months of use]. Patients will be required to have continuous apixaban use for ≥6 months without a gap of >30 days. The end of the initial 6 months of apixaban treatment following the index VTE event will be designated as the index date;; c) Were aged ≥18 years as of the index date; and; d) Had continuous health plan enrollment for ≥12 months prior to the index date.
• 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
• Estimated number of subjects:
  1000

Study design details

• Main study objective:
  The objectives of this study are to describe patient characteristics, treatment patterns and outcomes among unprovoked VTE patients who received apixaban treatment and either continued or discontinued apixaban after 6 months
• Data analysis plan:
  Means, medians, and standard deviations will be provided for continuous variables when performing descriptive analysis of continuous data. Numbers and percentages will be provided for dichotomous and polychotomous variables when performing descriptive analysis of categorical data. Bivariate comparisons of baseline characteristics and outcomes measures will be provided. Appropriate tests (eg, t-test, chi-square test) will be used based on the distribution of the measure. The cumulative incidence rate for clinical outcomes (major bleeding, CRNM, recurrent VTE) will be calculated. The incidence rate will be calculated as the number of patients who experience the event divided by the observed time at risk. All data analysis will be executed using statistical software STATA and SAS version 9.3/9.4.