title: Multiple-center evaluation of mortality associated with acute kidney injury in critically ill patients: a competing risks analysis.
abstract: BACKGROUND
  In this study, we aimed to assess the association between acute kidney injury (AKI) and mortality in critically ill patients using an original competing risks approach.
  
  
  METHODS
  Unselected patients admitted between 1997 and 2009 to 13 French medical or surgical intensive care units were included in this observational cohort study. AKI was defined according to the RIFLE criteria. The following data were recorded: baseline characteristics, daily serum creatinine level, daily Sequential Organ Failure Assessment (SOFA) score, vital status at hospital discharge and length of hospital stay. Patients were classified according to the maximum RIFLE class reached during their ICU stay. The association of AKI with hospital mortality with "discharge alive" considered as a competing event was assessed according to the Fine and Gray model.
  
  
  RESULTS
  Of the 8,639 study patients, 32.9% had AKI, of whom 19.1% received renal replacement therapy. Patients with AKI had higher crude mortality rates and longer lengths of hospital stay than patients without AKI. In the Fine and Gray model, independent risk factors for hospital mortality were the RIFLE classes Risk (sub-hazard ratio (SHR) 1.58 and 95% confidence interval (95% CI) 1.32 to 1.88; P < 0.0001), Injury (SHR 3.99 and 95% CI 3.43 to 4.65; P < 0.0001) and Failure (SHR 4.12 and 95% CI 3.55 to 4.79; P < 0.0001); nonrenal SOFA score (SHR 1.19 per point and 95% CI 1.18 to 1.21; P < 0.0001); McCabe class 3 (SHR 2.71 and 95% CI 2.34 to 3.15; P < 0.0001); and respiratory failure (SHR 3.08 and 95% CI 1.36 to 7.01; P < 0.01).
  
  
  CONCLUSIONS
  By using a competing risks approach, we confirm in this study that AKI affecting critically ill patients is associated with increased in-hospital mortality.
authors.affiliation: Medical-Surgical Intensive Care Unit, Avicenne Teaching Hospital, 125 Route de Stalingrad, Bobigny Cedex, France. christophe.clech@avc.aphp.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Clec'h
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gonzalez
authors.forename: Alexandre
authors.initials: A
authors.lastname: Lautrette
authors.forename: Molière
authors.initials: M
authors.lastname: Nguile-Makao
authors.forename: Maïté
authors.initials: M
authors.lastname: Garrouste-Orgeas
authors.forename: Samir
authors.initials: S
authors.lastname: Jamali
authors.forename: Dany
authors.initials: D
authors.lastname: Golgran-Toledano
authors.forename: Adrien
authors.initials: A
authors.lastname: Descorps-Declere
authors.forename: Frank
authors.initials: F
authors.lastname: Chemouni
authors.forename: Rebecca
authors.initials: R
authors.lastname: Hamidfar-Roy
authors.forename: Elie
authors.initials: E
authors.lastname: Azoulay
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Timsit
mesh_terms: D058186:Acute Kidney Injury / Q000401:mortality*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D016638:Critical Illness; D005260:Female; D005602:France / Q000453:epidemiology; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods