International audienceBACKGROUND: The lack of a well-designed prospective study of the determinants of urgent dialysis start led us to investigate its individual- and provider-related factors in patients seeing nephrologists. METHODS: CKD-REIN is a prospective cohort study that included 3033 patients with CKD (mean age, 67 years; 65% men; mean estimated glomerular filtration rate (eGFR), 32 mL/min/1.73 m2) from 40 nationally representative nephrology clinics from 2013-16, who were followed annually through 2020. Urgent-start dialysis was defined as that "initiated imminently or \textless 48 hours after presentation to correct life-threatening manifestations" according to KDIGO 2018. RESULTS: Over a 4-year (IQR, 3.0-4.8) median follow-up, 54...