Late nephrology referral and mortality among patients with end-stage renal disease: a propensity score analysis

Background. Late nephrology referral has been associated with adverse outcomes among patients with end-stage renal disease; however, its relationship to mortality is unclear. We examined the impact of timing of nephrology care relative to initiation of dialysis on mortality after initiation of dialysis. Methods. Data from the Dialysis Morbidity and Mortality Study - Wave II, a prospective study of incident dialysis patients, were used. Late referral (LR) was defined as first nephrology visit < 4 months and early referral (ER) as first nephrology visit greater than or equal to4 months prior to initiation of dialysis. Propensity scores (PS) were estimated using logistic regression to predict the probability that a given patient was LR. A Cox proportional hazards model was built to examine the association between timing of nephrology referral and mortality. Results. The cohort was comprised of 2195 patients: 54% were males, 66% were Caucasians, 26% were African-Americans and 33% were referred late. A Cox proportional hazards analysis demonstrated that compared with ER patients, LR patients had a 44% higher risk of death at 1 year after initiation of dialysis [hazards ratio (HR) = 1.44; 95% confidence interval (CI): 1.15-1.80], which remained significant after adjusting for quintiles of PS (HR = 1.42; 95% CI: 1.12-1.80). Conclusions. Among patients with chronic kidney disease (CKD) who initiated dialysis, LR was associated with higher risk of death at 1 year after initiation of dialysis compared with ER.