Anticoagulation treatment of cancer patients with deep or superficial leg vein thrombosis - a retrospective observational study of German statutory health insurance claims data (the CERTIFICAT initiative)

Background: Thrombosis is a common complication of cancer with a negative impact on quality of life and overall prognosis. Guidelines recommend low-molecular-weight heparin (LMWH) as initial and prolonged anticoagulation treatment. Little is known about current treatment patterns of these patients in ambulatory care. Patients and methods: The current retrospective observational study interrogates a large German statutory health insurance claims database in order to understand which kind of data can be extracted and analysed. An age- and sex-adjusted sample of about 4.1 million insured people from 2011 to 2016 could be used. Cancer patients with incident deep and superficial leg vein thrombosis were identified. Patients with preexisting cancer were allocated to a normal risk group; those who suffered from simultaneously diagnosed cancer and thrombosis were classified as high risk group. Results: We identified 322,600 patients with inpatient or outpatient documented cancer diagnosis in at least two different quarters within one year. 87,755 patients were identified with an incident deep or superficial vein thrombosis. 8,201 patients suffered from both cancer and incident thrombosis. 56.9% of the patients received an anticoagulation regimen with predominant LMWH prescription, 24.2% vitamin K antagonists, 17.2% direct oral anticoagulants; in 1.7% of patients, no predominant anticoagulant drug/regime could be identified. On average, patients were prescribed anticoagulants for 4.5 months. An estimate of clinically relevant gastrointestinal bleeding could be derived (1.8% of patients). Conclusions: The dataset allows assigning detailed information of anticoagulant prescriptions in ambulatory care to well-defined groups of cancer patients. A first analysis suggests that in Germany current medical care of patients with cancer-related deep or superficial vein thrombosis does rot entirely comply with guideline recommendations regarding type and duration of anticoagulation.