Adherence to apixaban for extended thromboprophylaxis after major abdominal or pelvic surgery for cancer: A prospective cohort study

J Surg Oncol. 2022 Aug;126(2):386-393. doi: 10.1002/jso.26876. Epub 2022 Apr 1.


Background: Due to lack of data, direct oral anticoagulants are not considered by guidelines for venous thromboembolism (VTE) prophylaxis after cancer surgery. Adherence to low-molecular-weight heparin injections in this setting is sometimes poor.

Aim: Analysis of adherence to oral apixaban for extended thromboprophylaxis.

Methods: Consecutive patients discharged after major surgery for abdominal/pelvic cancer and considered eligible for extended prophylaxis were offered apixaban 2.5 mg twice daily. Primary outcomes were adherence metrics-proportion of prescriptions filled, persistence (not prematurely discontinued), proportion of days covered (PDC) based on apixaban pill counts, and modified Morisky medication adherence scale at Days 28-30. Secondary outcomes were bleeding, VTE, and serious adverse events until Day 90.

Results: We included 53 patients, 51 were analyzed. Of 45 patients with prescriptions all had it filled (95% confidence interval [CI], 92%-100%). Persistence was 98% (95% CI, 90%-100%). PDC was ≥80% for 48 patients (94%; 95% CI, 84%-99%). We found good adherence (0/6 answers "yes") in 75% and moderate (1/6 answers "yes") in 25%. No major bleed or VTE occurred while on apixaban.

Conclusion: Our results support good adherence with apixaban for VTE prophylaxis up to 28 days after major abdominal or pelvic cancer surgery.

Keywords: apixaban; medication adherence; neoplasms; patient discharge; venous thromboembolism.

MeSH terms

  • Anticoagulants / therapeutic use
  • Hemorrhage / chemically induced
  • Hemorrhage / prevention & control
  • Humans
  • Pelvic Neoplasms* / surgery
  • Prospective Studies
  • Pyrazoles
  • Pyridones / therapeutic use
  • Venous Thromboembolism* / etiology
  • Venous Thromboembolism* / prevention & control


  • Anticoagulants
  • Pyrazoles
  • Pyridones
  • apixaban