Dynamic Patterns and Persistence of Anticoagulation Therapy in Patients with Venous Thromboembolism in South Korea: A Nationwide Cohort Study

Abstract

Background: Venous thromboembolism (VTE) is associated with increased morbidity, mortality, and health care expenditure. However, the comprehensive utilization of anticoagulation therapy in patients with VTE, especially regarding active cancer, in real-world practice remains unclear.

Objective: To describe the prescription, persistence, and patterns of anticoagulation therapy among patients with VTE stratified according to active cancer.

Methods: Using Korean nationwide claims data, we identified an incident, treatment-naïve cohort of patients with VTE from 2013 to 2019 and classified them according to the presence/absence of active cancer. We explored the secular trends, treatment patterns (e.g., discontinuation, interruption, and switch), and persistence of anticoagulation therapy.

Results: There were 48,504 and 7,255 patients without and with active cancer, respectively. Non-vitamin K antagonist oral anticoagulants (NOACs) were the most common anticoagulant in both groups (65.1 and 57.9%, respectively). The prescription of NOACs increased steeply over time, regardless of active cancer, whereas parenteral anticoagulants (PACs) plateaued and warfarin decreased sharply. A heterogeneous pattern was observed between the groups without and with active cancer (3-month persistence was 60.8, 62.9, 57.2, and 3.4%, respectively; 6-month persistence was 42.3, 33.5, 25.9, and 1.2% vs. 9.9%). Median durations of continuous anticoagulant therapy for warfarin, NOAC, and PAC were 183, 147, and 3 days in nonactive cancer patients, and 121, 117, and 44 days in active cancer patients.

Conclusion: Our findings suggest that there were substantial differences in persistence, patterns, and patient characteristics of anticoagulant therapy based on index anticoagulant and active cancer.

Fig. 1

Inclusion and exclusion criteria of the study. *Record of active cancer was defined as a first diagnosis of cancer with a V code within the 6-month period prior to the index date; or receiving anticancer treatment under a cancer diagnosis with a V code within the 6-month period prior to the index date. ^† Warfarin-based therapy included either a PAC with warfarin or warfarin alone. ^‡ NOAC-based therapy included either a PAC with a NOAC or a NOAC alone. HIRA, Health Insurance and Review Assessment service; LMWH, low-molecular-weight heparin; NOAC, non-vitamin K antagonist; PACs, parenteral anticoagulants; VTE, venous thromboembolism.

Fig. 2

Secular trends in the initial anticoagulant therapy in patients with venous thromboembolism stratified according to the presence/absence of active cancer.

Fig. 3

Kaplan–Meier plot showing the persistence of treatment with the index anticoagulant among patients with venous thromboembolism who were stratified according to the presence/absence of active cancer. p -Values for the overall Kaplan–Meier curve and for each individual index anticoagulant comparison were <0.0001 at 3 and 6 months, regardless of active cancer. The Scheffé's method was applied to adjust multiple comparisons for the log-rank test. NOAC, non-vitamin K antagonist oral anticoagulant; PAC, parenteral anticoagulant.