Glomerular Filtration Rate and Initiation of Dialysis

The proportion of patients with advanced chronic kidney disease (CKD) initiating dialysis at higher glomerular filtration rate (GFR) has increased over the past decade. Recent data suggest that it may be associated with increased mortality. The goal of this analysis was to compare survival outcomes in patients with early and late start dialysis. We performed a retrospective analysis of hemodialysis (HD) incident patients from 1 January 2010 to 30 September 2014. Patients were classified into two groups by estimated GFR at dialysis initiation (eGFR ≥10: early start and <10 mL/min per 1.73m² : late start). Logistic regression was used to evaluate factors associated with early and late dialysis start, and Kaplan-Meier graphs and Cox regression models in survival analysis. In this total incident population (N = 235), 42 patients had an early dialysis start. Compared with the group with an eGFR of <10 mL/min per 1.73 m² at dialysis start, a Cox model showed an incremental increase in mortality associated with earlier dialysis start (P = 0.027). Independent factors (P < 0.05) associated with mortality in the multivariable Cox model in early dialysis start were: hypertension (HR 9.32, CI: 1.34-17.87), diabetes (HR 1.8, CI: 0.4-13.2) and albumin <3.5 g/dL (HR 1.5, CI: 0.8-6.2). Older patients (HR 0.084, CI: 0.008-0.863) with low phosphorus levels (HR 0.02, CI: 0.0-0.527) also had statistically significant results, although they showed a reduced risk of mortality. Early dialysis initiation was associated with an increased mortality risk, arguing against aggressive early dialysis initiation based primarily on eGFR alone.