title: Impact of timing of initiation of dialysis on mortality.
abstract: Previous studies showed that sicker patients were initiated on dialysis at higher GFR as estimated by the Modification of Diet in Renal Disease (MDRD) formula. It was previously shown that patients with low creatinine production were malnourished and had low serum creatinine levels and creatinine clearances (CrCl) but high MDRD GFR at initiation of dialysis. Therefore, a propensity score approach was used to examine the associations of MDRD GFR and measured CrCl at the initiation of dialysis with subsequent mortality. Baseline data and outcomes were obtained from the Dialysis Morbidity Mortality Study Wave II. Propensity scores for early initiation derived by logistic regression were used in Cox models to examine mortality. Each 5-ml/min increase in MDRD GFR at initiation of dialysis in the entire cohort was associated with increased hazard of death in multivariable Cox model (hazard ratio [HR] 1.14; P = 0.002). In the subgroup of patients with reported CrCl, higher MDRD GFR was associated with increased risk of death (for each 5-ml/min increase, HR 1.27; P < 0.001) but not CrCl (for each 5-ml/min increase, HR 0.98; P = 0.81). These divergent results might reflect erroneous GFR estimation by the MDRD formula. Furthermore, these data do not support earlier initiation of dialysis. Therefore, for patients without clinical indications for initiation of dialysis, the appropriate GFR level for initiation of dialysis is unknown.
authors.affiliation: Renal Section, Salt Lake VA Healthcare System, Division of Nephrology & Hypertension, and Division of Clinical Epidemiology, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA. Srinivasan.beddhu@hsc.utah.edu
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Beddhu
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Samore
authors.forename: Mark S
authors.initials: MS
authors.lastname: Roberts
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Stoddard
authors.forename: Nirupama
authors.initials: N
authors.lastname: Ramkumar
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Pappas
authors.forename: Alfred K
authors.initials: AK
authors.lastname: Cheung
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003404:Creatinine / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012720:Severity of Illness Index; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D003404:Creatinine