Early referral to a nephrologist improved patient survival: prospective cohort study for end-stage renal disease in Korea

Abstract

The timing of referral to a nephrologist may influence the outcome of chronic kidney disease patients, but its impact has not been evaluated thoroughly. The results of a recent study showing an association between early referral and patient survival are still being debated. A total of 1028 patients newly diagnosed as end-stage renal disease (ESRD) from July 2008 to October 2011 were enrolled. Early referral (ER) was defined as patients meeting with a nephrologist more than a year before dialysis and dialysis education were provided, and all others were considered late referral (LR). The relationship of referral pattern with mortality in ESRD patients was explored using a Cox proportional hazards regression models. Time from referral to dialysis was significantly longer in 599 ER patients than in 429 LR patients (62.3 ± 58.9 versus 2.9 ± 3.4 months, P<0.001). Emergency HD using a temporary vascular catheter was required in 485 (47.2%) out of all patients and in 262 (43.7%) of ER compared with 223 (52.0%) of LR (P = 0.009). After 2 years of follow-up, the survival rate in ER was better than that in LR (hazard ratio [HR] 2.38, 95% confidence interval [CI] 1.27-4.45, P = 0.007). In patients with diabetes nephropathy, patient survival was also significantly higher in ER than in LR (HR 4.74, 95% CI 1.73-13.00, P = 0.002). With increasing age, HR also increased. Timely referral to a nephrologist in the predialytic stage is associated with reduced mortality.

Figure 1. Pattern of emergency dialysis using a temporary vascular catheter according to the timing of referral.

Early referral were defined as the patient's first encounter with a nephrologist occurring more than 1 year before first dialysis, with education about dialysis prior to initiation of dialysis, and all others were considered late referral (P = 0.009).

Figure 2. Kaplan-Meier survival curve by timing of referral.

(A) Total patients, adjusted for age, gender, modified CCI, BMI, eGFR, serum hemoglobin, calcium, iPTH, uric acid, triglycerides, total cholesterol, and HDL cholesterol. (B) DM ESRD patients, adjusted for age, gender, modified CCI, BMI, eGFR, serum hemoglobin, calcium, iPTH, uric acid, triglycerides, total cholesterol, and HDL cholesterol.

Figure 3. Relationship between log relative hazard for mortality and age according to timing of referral.

(A) Total patients, adjusted for age, gender, modified CCI, BMI, eGFR, serum hemoglobin, calcium, iPTH, uric acid, triglycerides, total cholesterol, and HDL cholesterol. (B) DM ESRD patients, adjusted for age, gender, modified CCI, BMI, eGFR, serum hemoglobin, calcium, iPTH, uric acid, triglycerides, total cholesterol, and HDL cholesterol.