A multi-centre evaluation of the RIFLE criteria for early acute kidney injury in critically ill patients

Nephrol Dial Transplant. 2008 Apr;23(4):1203-10. doi: 10.1093/ndt/gfm744. Epub 2007 Oct 25.


Background: The Acute Dialysis Quality Initiative Working Group recently developed the RIFLE criteria, a consensus definition for acute kidney injury (AKI). We sought to evaluate the RIFLE criteria on the day of ICU admission in a large heterogenous population of critically ill patients.

Methods: Retrospective interrogation of prospectively collected data from the Australian New Zealand Intensive Care Society Adult Patient Database. We evaluated 120 123 patients admitted for >/=24 h from 1 January 2000 to 31 December 2005 from 57 ICUs across Australia.

Results: The median (IQR) age was 64.3 (50.8-75.4) years, 59.5% were male, 28.6% had co-morbid disease, 50.3% were medical admissions and the initial mean (+/-SD) APACHEII score was 16.9 (+/-7.7). According to the RIFLE criteria, on the day of admission, AKI occurred in 36.1%, with a maximum RIFLE category of Risk in 16.3%, Injury in 13.6%, and Failure 6.3%. AKI, defined by any RIFLE category, was associated with an increase in hospital mortality (OR 3.29, 95% CI 3.19-3.41, P < 0.0001). The crude hospital mortality stratified by RIFLE category was 17.9% for Risk, 27.7% for Injury and 33.2% for Failure. By multivariable analysis, each RIFLE category was independently associated with hospital mortality (OR: Risk 1.58, Injury 2.54 and Failure 3.22).

Conclusion: In a large heterogenous cohort of critically ill patients, the RIFLE criteria classified >36% with AKI on the day of admission. For successive increases in severity of RIFLE category, there were increases in hospital mortality. The RIFLE criteria represent a simple tool for the detection and classification of AKI and for correlation with clinical outcomes.

Publication types

  • Comparative Study
  • Evaluation Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / classification*
  • Acute Kidney Injury / mortality
  • Acute Kidney Injury / therapy
  • Aged
  • Critical Illness / mortality
  • Critical Illness / therapy*
  • Female
  • Follow-Up Studies
  • Hospital Mortality / trends
  • Humans
  • Intensive Care Units / standards*
  • Length of Stay / trends
  • Male
  • Middle Aged
  • Patient Discharge / trends
  • Quality Assurance, Health Care / methods*
  • Renal Dialysis / standards*
  • Retrospective Studies
  • Risk Assessment
  • Severity of Illness Index
  • Time Factors
  • Victoria / epidemiology