Timing of nephrology referral and initiation of dialysis as predictors for survival in hemodialysis patients: 5-year follow-up analysis.

BACKGROUND: A consensus about the optimal timing of dialysis initiation is still controversial. Thus, the goal of this analysis was to compare outcomes in patients with early and late referral with early and late initiation of hemodialysis (HD).
METHODS: We studied 190 patients (mean age 52.03±14.22) who were initiated on HD between 1994 and 2004. Patients who received regular nephrology care during 12 months before HD initiation were categorized as early referrals (ER) and those without nephrology care were late referrals (LR). The early start (E-start) was defined by the estimated GFR (eGFR) at start of HD≥7.5 mL/min/1.73 m2, and the late start (L-start) by eGFR of <7.5 mL/min/1.73 m2. The four groups of patients (ER with E-start and L-start; LR with E-start and L-start) were prospectively followed in the next 60 months after HD initiation.
RESULTS: During the follow-up, 43.3% of E-start and 43.2% of L-start patients died, without significant difference in survival between the groups [HR for L-start vs. E-start=1.06 (95% CI 0.69-1.62); p=0.797]. When survival between ER and LR groups was compared (28.1% patients in the ER and 53.2% in the LR died), there was significant difference in survival [HR for LR vs. ER=2.16 (95% CI 1.28-3.65); p=0.004]. Compared with patients with ER and L-start, higher mortality was observed among those with LR and L-start [HR 3.51 (95% CI 1.48-8.35); p=0.004] and LR with E-start [HR 2.79 (95% CI 1.16-6.7); p=0.022]. There was no significant difference between patients in ER with L-start and ER with E-start.
CONCLUSIONS: Our study showed that ER above 12 months before HD initiation and L-start of dialysis was associated with a reduced mortality risk in HD patients.