Abstract Number: PB2462
Meeting: ISTH 2020 Congress
Theme: Venous Thromboembolism and Cardioembolism » VTE Treatment
Background: Data on oral anticoagulants (OAC) use among Venous Thromboembolism (VTE) patients in Norway is limited.
Aims: Describe demographic and clinical characteristics, trends and treatment patterns of OACs in VTE patients in Norway between 2013 and 2017.
Methods: Cohort study using prospectively collected data from the national registries in Norway between 2013 and 2017. Patients were included if they had a VTE diagnosis followed by an OAC dispensation within 30 days in this time-frame. Patients were excluded if they had presence of atrial fibrillation or a prior OAC. Kaplan Meier methods were used to assess the duration of treatment. The study was approved by the Regional Ethics Committee (2017/1328-9).
Results: 3,557 warfarin, 3,088 apixaban and 5,828 rivaroxaban patients were identified. Counts for dabigatran and edoxaban were low and are not described further. Warfarin patients were younger than apixaban (median [IQR]: 64 [26] vs. 66 [24] years; p=0.0045), but older than rivaroxaban (61 [24]; p< 0.0001). Gender distributions were similar across all groups (%female 48.5 (warfarin), 46.4 (apixaban), 43.6 (rivaroxaban)). The most prevalent comorbidity in all groups was hypertension (44%). From 2013 to 2017, of total OAC use, apixaban increased 54.5%, rivaroxaban 5.7%, warfarin declined 60.2% (Figure 1). A higher proportion of apixaban patients were persistent after 12 months of follow-up compared with warfarin, (mostly apparent after 6 months; log-rank: p< 0.0001); no difference was observed between rivaroxaban and warfarin patients (p=0.36). More than three quarters of patients, irrespective of OAC, were persistent at 3 months. At 12 months, 30.8% of patients were still persistent on apixaban, followed by 21.9% on warfarin and 19.2% on rivaroxaban (Table 1).
Conclusions: Between 2013 and 2017, apixaban and rivaroxaban use in VTE patients increased in Norway, warfarin use declined. A higher proportion of apixaban patients were persistent on treatment over time followed by warfarin and rivaroxaban.
| Kaplan-Meier estimates: | Warfarin N=3,557 | Apixaban N=3,088 | Rivaroxaban N=5,828 | |
| Length of Time on Index Therapy, months: | Median (IQR) | 6.3 (3.4-10.6) | 6.4 (3.7-15.9) | 6.0 (3.9-9.2) |
| Patients Persistent on Treatment at Certain Timepoints, months: | ||||
| 0-3 | % (95%CI) | 79.7 (78.3-81.0) | 83.7 (82.3-85.0) | 87.4 (86.5-88.2) |
| 0-6 | % (95%CI) | 53.1 (51.4-54.7) | 53.9 (51.9-55.8) | 49.7 (48.4-51.1) |
| 0-9 | % (95%CI) | 30.3 (28.8-31.8) | 36.5 (34.5-38.4) | 25.4 (24.3-26.6) |
| 0-12 | % (95%CI) | 21.9 (20.6-23.4) | 30.8 (28.8-32.8) | 19.2 (18.2-20.3) |
[Table 1. Median Length of Time on Therapy and Percentage of Patients Persistent on Index Therapy at Certain Timepoints (Kaplan Meier estimates)]
[Figure 1. Distribution of OACs Used Among Newly Treated Incident VTE Population in Norway]
To cite this abstract in AMA style:
Ghanima W, Halvorsen S, Brodin E, Graham S, Schultze A, Donaldson R, Carroll R, Ulvestad M, Lambrelli D. Oral Anticoagulation Therapy for Venous Thromboembolism in Norway: Patient Characteristics, Treatment Trends and Patterns [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/oral-anticoagulation-therapy-for-venous-thromboembolism-in-norway-patient-characteristics-treatment-trends-and-patterns/. Accessed September 24, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/oral-anticoagulation-therapy-for-venous-thromboembolism-in-norway-patient-characteristics-treatment-trends-and-patterns/