Ideal Timing and Predialysis Nephrology Care Duration for Dialysis Initiation: From Analysis of Japanese Dialysis Initiation Survey

Previous studies have suggested that early initiation of dialysis therapy was not superior in terms of patient survival. In this study, we analyzed the effects of renal function at the start of renal replacement therapy (RRT), duration of nephrology care, and comorbidity on 12-month survival of end-stage renal disease (ESRD) patients. The subjects in this study were 9695 new ESRD patients who started RRT in 2007. The average age of the subjects was 67.5years, 64.1% of the subjects were male, and 42.9% had diabetes. During the 12-month period after the start of RRT, 1546 patients died, and 35 patients received renal transplantation. Average estimated glomerular filtration rate (eGFR) at the initiation of dialysis was 6.52±4.20mL/min/1.73m². By unadjusted logistic analysis, one-year Odds Ratio (OR) of mortality in patients with eGFR more than 4-6mL/min/1.73m² was increased with increased eGFR at dialysis initiation, but the OR was identical among the groups with eGFR less than 4mL/min/1.73m². After adjustment for age, gender, underlying renal diseases, and other clinical characteristics at dialysis initiation, OR was identical among the groups with eGFR less than 8mL/min/1.73m². Furthermore, an OR increment was observed in eGFR less than 4mL/min/1.73m² group. In terms of the duration of nephrology care before dialysis initiation, 6months or longer of nephrology care significantly decreased the OR of mortality after adjustment of covariance. Not only patients with sufficient residual renal function at the initiation of dialysis, but also patients with very low eGFR at the initiation of dialysis showed poor survival.