Early start of hemodialysis may be harmful.

Background: A dramatic increase in the "early start" of dialysis with an estimated glomerular filtration rate (eGFR) at least 10 mL/min/1.73 m(2) has occurred in the United States since at least 1996. Several recent studies have reported a comorbidity-adjusted survival disadvantage of early start of dialysis. The current study examines a relatively "healthy" dialysis cohort to minimize confounding issues and determine whether early initiation of hemodialysis is associated with a survival benefit or harm.

Methods: We examined demographics, year of dialysis initiation, primary etiology of renal failure, and body mass index, hemoglobin, and serum albumin levels in 81,176 nondiabetic, 20- to 64-year-old, in-center incident hemodialysis patients with no reported comorbidity besides hypertension. We compared survival, using a piecewise proportional hazards model to estimate covariate-adjusted mortality hazard ratios (HRs) for eGFR at the time of initiation of dialysis. We also performed time-dependent adjusted analysis stratified by initial serum albumin levels lower than 2.5 g/dL, 2.5 to 3.49 g/dL, and 3.5 g/dL or higher (the "healthiest" group [HG]).

Results: Unadjusted 1-year mortality by eGFR ranged from 6.8% in the reference group (eGFR <5.0 mL/min/1.73 m(2)) to 20.1% in the highest eGFR group (≥15.0 mL/min/1.73 m(2)). Compared with the reference group, the HR for the HG was 1.27 (eGFR, 5.0-9.9 mL/min/1.73 m(2)), 1.53 (eGFR, 10.0-14.9 mL/min/1.73 m(2)), and 2.18 (eGFR ≥15.0 mL/min/1.73 m(2)) and ranged from 1.50 to 3.53 mL/min/1.73 m(2) in the first year of dialysis for the early-start group.

Conclusion: The increased HR during hemodialysis associated with early start in the healthiest group of patients undergoing dialysis indicates that early start of dialysis may be harmful.