Comparison of 2 acute renal failure severity scores to general scoring systems in the critically ill.
BACKGROUND
Several proposed definitions for acute renal failure (ARF) exist, but little is known of their significance in clinical practice. We evaluated the ability to predict hospital mortality in 2 ARF-specific severity-of-illness scoring methods, the Risk, Injury, Failure, Loss, End-Stage Renal Disease (RIFLE) score and the score presented by Bellomo et al in 2001.


METHODS
The study included 668 consecutive patients with 694 treatment episodes treated in 2 intensive care units (ICUs) in a university hospital within 11 months. ARF prevalence was classified according to the RIFLE and Bellomo scores. As references, we evaluated 2 general severity-of-illness scoring systems, the admission Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores.


RESULTS
Admission SOFA scores and maximum RIFLE scores for the first 3 days in the ICU were independent predictors of hospital mortality by means of forward conditional logistic regression. In receiver operating characteristic analysis, SOFA and APACHE II scores performed better than ARF-specific scores, and discriminative powers for hospital mortality were only moderate for the RIFLE and Bellomo scores: areas under the curve were 0.653 (95% confidence interval, 0.588 to 0.719) and 0.587 (95% confidence interval, 0.514 to 0.660), respectively.


CONCLUSIONS
Neither of the ARF-specific scoring methods presented good discriminative power regarding hospital mortality. However, maximum RIFLE score for the first 3 days in the ICU was found to be an independent predictor of hospital mortality, along with admission SOFA score.
Ahlström
Annika
A
Intensive Care Unit, Department of Surgery, Division of Anaesthesiology and Intensive Care Medicine, Helsinki University Central Hospital, Helsinki, Finland. annika.ahlstrom@helsinki.fi
Kuitunen
Anne
A
Peltonen
Seija
S
Hynninen
Marja
M
Tallgren
Minna
M
Aaltonen
Janne
J
Pettilä
Ville
V
D000208:Acute Disease; D000368:Aged; D016638:Critical Illness; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010343:Patient Admission; D011237:Predictive Value of Tests; D012372:ROC Curve; D051437:Renal Insufficiency / Q000145:classification* / Q000473:pathology*; D012720:Severity of Illness Index