Early Nephrology Referral Is Associated With Prolonged Survival in Hemodialysis Patients Even After Exclusion of Lead-Time Bias

Background: Early nephrology referral (ER) has been suggested to lower morbidity and mortality in dialysis patients, but the nature of the association has been criticized as possibly because of lead-time bias. This study aims to evaluate if ER is associated with improved survival of hemodialysis patients when the lead-time bias is excluded. Methods: A total of 192 hemodialysis patients from a medical center and a regional hospital were enrolled in the period from January 1997 to December 2006. ER and late referral (LR) were defined as referral to nephrologists greater or less than 6 months, respectively, before the initiation of hemodialysis. Follow-up of clinical course in all patients was timed from the date at which estimate glomerular filtration rate was estimated to be 15 mL/min/1.73m(2). The relative overall survival was analyzed by Cox-regression adjusted for their demographic and comorbid conditions Results: Compared with LR patients, ER patients were less likely to have hypoalbuminemia in the beginning of hemodialysis, more likely to have received erythropoietin or phosphate binder therapy, more likely to have a vascular access created before the first hemodialysis, and had a slower rate of renal function decline before hemodialysis. In multivariate analysis, LR (hazard ratio: 2.827; P = 0.049) and diabetes mellitus were both independently associated with increased mortality risk. The survival benefits of ER seem to be originated from the period before initiation of renal replacement therapy. Conclusions: Our findings show that ER is significantly associated with prolonged survival after exclusion of lead-time bias, which is consistent with ER being associated with better clinical outcomes in hemodialysis patients.