Fig. 1.

Patient selection criteria. The figure illustrates the process and selection criteria used to identify patient records from the databases used in this study. Patient records were included if the patient had both CKD (defined by ICD-9-CM codes 585.1–585.9 or ICD-10-CM codes N18.1–N18.9) and a diagnosis of VTE, and was treated with either apixaban or warfarin within 30 days after the index VTE. Patients were excluded on the basis of the following criteria: age (Medicare only), health insurance continuous enrollment status, medical history, and medication use. CKD, chronic kidney disease; CM, clinical modification; ICD, International Classification of Diseases; OAC, oral anticoagulant; PAC, parenteral anticoagulant; VTE, venous thromboembolism. ^a MarketScan: September 2018; Optum and Humana: December 2018; PharMetrics: March 2019; CMS Medicare: December 2016.