Database analysis of venous thromboembolism treatment patterns in inpatient vs outpatient settings

Background: The standard of care for patients with venous thromboembolism (VTE) has been treatment with parenteral anticoagulation therapy, such as low-molecular weight heparin (LMWH), followed by long-term treatment with an oral vitamin K antagonist, such as warfarin. In recent years, novel oral anticoagulants have been approved for treatment and prevention of recurrent venous thromboembolism. There is little in the literature regarding real-world treatment patterns following outpatient diagnosis of VTE. Objectives: To describe the characteristics of outpatient-diagnosed patients treated for VTE in inpatient and outpatient settings, and characterize treatment patterns for initial treatment and secondary prevention of VTE. Methods: This study was a non-interventional retrospective observational cohort study conducted within an integrated health care system. Patients were identified using an algorithm comprised of VTE ICD-9 codes in combination with imaging procedures and treatments consistent with VTE. VTEs were verified by medical record review. Results: Inpatient-treated subjects had a mean age at Index (date of VTE diagnosis) of 65.7 (±15.1) years while outpatient-treated had a mean age of 61.6 (±16.3) years (p = 0.026). Eighty percent of all patients experienced an isolated deep vein thrombosis (DVT), 10% experienced isolated pulmonary embolism (PE) and 10% experienced PE with DVT. A significantly greater proportion of subjects with PE, alone or with DVT, were treated as inpatient (90%) and a greater proportion of subjects with isolated DVT were treated as outpatient (75%) (p \u3c 0.001). Initial anticoagulant therapy consisted of LMWH, warfarin and/or heparin for 90%, 29% or 2% of outpatient-treated and 74%, 88% or 82% of inpatient-treated patients, respectively. Extended anticoagulation consisted primarily of warfarin and/or LMWH for 87% and 81% of outpatient-treated and 76% and 58% of inpatient-treated patients, respectively. Conclusions: Patients with DVT were more likely to be treated as outpatients and those with any PE were more likely to be hospitalized. Hospitalized patients were older and had more comorbidities and risk factors. Patients treated as outpatients received LMWH as initial treatment but 30% of them also received warfarin. Outpatient-treated patients received LMWH and warfarin as extended therapy. Patients who were hospitalized received LMWH and/or warfarin and/or heparin as initial treatment and received warfarin, and to a lesser extent, LMWH as extended therapy