Factors associated with IVCF use among patients with melanoma, kidney, breast, or lung cancers and a VTE event at hospital admission, California, 2005 to 2017. ^Contraindication to anticoagulation. The reference category corresponds to patients with no contraindications. The model was also adjusted for VTE age, prior VTE, sex, race/ethnicity, insurance, stage at diagnosis, and comorbidities at cancer diagnosis. LE, lower extremity; NOS, not otherwise specified.