Trends and factors associated with outpatient anticoagulant treatment initiation among VTE patients with active cancer

Abstract

Background: Patients with venous thromboembolism (VTE) and cancer are at higher risk of recurrent VTE and mortality. Clinical guidelines recommend anticoagulant treatment for these patients. This study assessed trends in outpatient anticoagulant treatment and factors associated with this treatment initiation in outpatient setting among this high-risk patient population.

Objective: To study trends and factors associated with anticoagulant treatment initiation among patients with VTE and cancer.

Methods: VTE cancer patients age ≥65 were identified from the SEER-Medicare database from 01JAN2014-31DEC2019. Patients were enrolled for ≥6 months prior to their first VTE (i.e. index event) and without evidence of other reasons for anticoagulation (i.e., atrial fibrillation). Patients were also required to be enrolled for ≥30 days after index. Cancer status was identified from SEER or Medicare database in the 6 months pre- through 30 days post-VTE. Patients were classified into treated or untreated cohorts depending on whether they initiated outpatient anticoagulant treatment within 30 days post-index. The trends of treated vs. untreated were evaluated by quarter. Logistic regression was used to identify demographic-, VTE-, cancer- and comorbid-related factors associated with anticoagulant treatment initiation.

Results: A total of 28,468 VTE-cancer patients met all study criteria. Of these, ~46 % initiated outpatient anticoagulant treatment within 30 days, and ~54 % did not. The above rates were stable from 2014 to 2019. Factors such as VTE diagnosis in inpatient setting, pulmonary embolism (PE) diagnosis, and pancreatic cancer were associated with increased odds whereas bleeding history and some comorbid factors were associated with decreased odds of initiating anticoagulant treatment.

Conclusion: Over half of VTE patients with cancer did not initiate outpatient anticoagulant treatment within the first 30-days after VTE diagnosis. This trend was stable from 2014 to 2019. A range of cancer-, VTE-, and comorbid-related factors were associated with the likelihood of the treatment initiation.

Keywords: Anticoagulants; Cancer; Venous thromboembolism.