Duration of predialysis nephrological care and mortality after dialysis initiation

The duration of predialysis nephrological care that can reduce all-cause and cardiovascular mortality after dialysis initiation has not been clarified.

A total of 1117 patients who started chronic dialysis treatment from 2006 to 2015 at Osaka General Medical Center were analyzed. Independent risk factors associated with all-cause and cardiovascular mortality after dialysis initiation and early death (death within 12 months after dialysis initiation) were identified using Cox proportional hazards analysis. Moreover, the duration of predialysis nephrology care that could reduce mortality was explored using several different definitions of early referral as well as "6 months" commonly used in previous studies.

Of 1117 patients, 834 were referred 6 months before dialysis initiation. During the follow-up period (median, 34 months), 324 patients died after dialysis initiation. Although multivariate Cox analysis did not show a favorable association between early referral of "6 months before dialysis initiation" and all-cause and cardiovascular mortality, 20-month predialysis nephrological care was associated with better first-year overall survival after dialysis initiation (hazard ratio 0.58; 95% confidence interval 0.35-0.98; P = 0.040).

More than 6 months nephrological care before dialysis initiation was not early enough to reduce all-cause and cardiovascular mortality after dialysis initiation. Our results suggest that nephrology referral 20 months before dialysis initiation would be necessary to reduce first-year overall survival after dialysis initiation.