Ratio of blood urea nitrogen to serum creatinine at initiation of dialysis is associated with mortality: a multicenter prospective cohort study

Some studies have shown that the estimated glomerular filtration rate (eGFR) at the time of initiating dialysis was associated with mortality. However, the relationship between ratio of blood urea nitrogen to serum creatinine (BUN/Cr) and mortality is unknown. The study was a multicenter, prospective cohort analysis including 1520 patients. Patients were classified into four quartiles based on the BUN/Cr ratio at the dialysis initiation, with Q1 having the lowest ratio and Q4 the highest. All-cause mortality after initiating dialysis was compared using the log-rank test. All-cause mortality of Q1, Q2, and Q3 was compared with that of Q4 using multivariate Cox proportional hazard regression analysis. Moreover, we compared the renal parameters including BUN/Cr ratio, eGFR, and creatinine clearance for sensitivity and specificity using receiver operative characteristic (ROC) curve. Significant differences were observed in all-cause mortality among the four groups (p