Discrepancies between the use of MDRD-4 IDMS and CKD-EPI equations, instead of the Cockcroft- Gault equation, in the determination of the dosage of direct oral anticoagulants in patients with non-valvular atrial fibrillation - Pérez Cabeza, AI; Chinchurreta Capote, PA (Med Clin (Barc), 2018)