Background: People with advanced cancer are at high risk for venous thromboembolic events (VTE). Trial data suggests that low molecular weight heparins (LMWH) may decrease recurrent thrombosis compared to warfarin for cancer patients with VTE, although no changes in bleeding or overall survival have been observed. However, both anticoagulation strategies have trade-offs, such as need for monitoring and mode of administration, and the use of these therapies and their effectiveness in real-world populations have not been well studied.
Objective: To evaluate the outcomes of recurrent thrombosis, bleeding events, and survival for advanced cancer patients treated with various anticoagulation strategies.
Study Design: Retrospective cohort study.
Methods: This study will compare the effectiveness and safety of different anticoagulation strategies for patients with advanced cancer who have had a first VTE. Investigators will combine Medicare and cancer registry data to develop algorithms for identifying advanced cancer patients using Medicare claims. These algorithms will be used to define a large cohort of patients from typical practice settings with advanced cancer and VTE. By using statistical methods that adjust for differences between patients treated with different types of anticoagulation, investigators will compare the effectiveness of each anticoagulant treatment at preventing VTE or death and the safety of each treatment in terms of the rate of bleeding complications. A clinical data repository will provide more detailed information on the drivers of treatment decisions and the role of medication adherence in the development of recurrent VTEs and bleeding events. Evaluating outcomes for complicated patients like those with advanced cancer and VTE can be difficult, since patients may have multiple events during the observation period, complicating the calculation of rates for any one event. The investigators will explore sophisticated statistical methods for measuring event rates most accurately when patients are at risk of multiple outcomes.
Expected Outputs: Scientific Reports.
Expected Project Completion Date: Fall 2011.