Early Nephrology Referral 6 Months Before Dialysis Initiation Can Reduce Early Death But Does Not Improve Long-Term Cardiovascular Outcome on Dialysis

Background: There is a paucity of studies on whether early referral (ER) to nephrologist could reduce cardiovascular mortality on dialysis, and the length of pre-dialysis nephrological care needed to reduce mortality on dialysis. Methods and Results: A total of 604 consecutive patients who started dialysis between 2001 and 2009 in Senshu region, Osaka, Japan were analyzed. Non-linear associations between mortality and pre-dialysis duration of nephrological care were assessed using restricted cubic spline function, and predictors for death analyzed on Cox modeling. A total of 31.6%, 18.2%, 11.3% and 6.1% of patients had >12, 24, 36 and 48 months of pre-dialysis care, respectively. A total of 258 patients (42.7%) were categorized as ER (>= 6 months pre-dialysis duration). During the follow-up period (median, 31.1 months), 218 patients died (cardiovascular, n=70; infection, n=69). Although patients with late referral (LR) had a proxy of inappropriate pre-dialysis care compared with the ER group, Cox multivariate analysis failed to show a favorable association between ER and cardiovascular outcome. In contrast, a deleterious effect of LR on overall survival was observed but was limited only to the first 12 months of dialysis (HR, 1.957; 95% CI: 1.104-3.469; P=0.021), but not observed thereafter. Conclusions: Current pre-dialysis nephrological care may reduce short-term mortality but may not improve cardiovascular mortality after dialysis initiation.