Effectiveness and Safety of Enoxaparin: Higher versus Standard Dose for Thromboprophylaxis in Patients of Varying Body Mass Index – A Retrospective Observational Cohort Study Using Real World EHR and Claims Data

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

  Effectiveness study (incl. comparative)

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Anatomical Therapeutic Chemical (ATC) code:
  (B01AB05) enoxaparin

  enoxaparin
• Medical condition to be studied:
  Thrombosis prophylaxis

  Obesity
• Additional medical condition(s):
  Venous thromboembolism prophylaxis in medically ill patients and moderate to high risk surgical patients including obese patients

Population studied

• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Estimated number of subjects:
  72000

Study design details

• Main study objective:
  To evaluate the impact of higher as compared with standard daily dose of enoxaparin on the risk of VTE and MBE at 3-months (primary effectiveness and safety endpoints) in hospitalized medically ill patients and in surgical patients (bariatric and non-bariatric settings).
• Outcomes:
  The risk of VTE and MBE at 3-months, 1. Risk of VTE and MBE in obese patients treated with higher versus standard daily dose of enoxaparin, in strata of medical or surgical setting, age, sex, VTE history, MBE history, treatment duration, dosing schedule, and surgery type. 2. Impact of daily dose of in pre-specified patients by cluster analysis, on VTE and MBE risks, separately in hospitalized medically ill and in surgical patients.
• Data analysis plan:
  Primary objective: Patients treated with higher and standard daily dose of enoxaparin will be matched on propensity score (PS). Kaplan- Meier method will be used to compare the time to the first outcomes between the cohorts. Cox proportional hazards regression will be used to estimate the hazard ratio (with 95% confidence intervals) for time to VTE and MBE. Covariates included in the PS that are unbalanced after the PS-matching will be candidate covariates for adjustment in the Cox model. The analyses will be stratified by BMI category. Sensitivity analyses will be performed. Secondary objective 1 will be analyzed as for the primary objective, exclusively among obese patients and using the patient and treatment characteristics as stratification variables. Secondary objective 2 will use cluster analysis to identify patient clusters in medically ill and surgical patients separately. The relationship between identified patient cluster memberships with VTE and MBE will be analyzed.