[Severity assessment by APACHE III system in Spain]

To assess the performance of the prediction equation of the APACHE(Acute Physiology Age and Chronic Health Evaluation) III prognostic scoring system when applied in Spain.

Prospective multicenter cohort study that included 10786 adult patients from 86 Spanish intensive care units (ICU). Data collection during first 24 hours of admission: acute physiology score, age and comorbilties,for calculating APACHE III score; treatment location prior to ICU admission and main diagnosis admission category for applying the mortality prediction equation of APACHE III system. Main outcome was observed hospital mortality.

Age was 57.74 (0.16); 68% males. Non-operative patients represented 76% of sample. APACHE III score was 53.75(0.26); observed and predicted hospital mortality were 21.2% and 19.8% respectively, with a standardized mortality ration of 1.07. The Chi2 Hosmer-Lemershow statistic was (H) 135.6, (C) 133.91: p < 0.001. The area under the Receiver Operating Curve (ROC) was 0.808, and correct classification at mortality risk of 50% was 82%. Uniformity of fit was better for non-operative diagnoses and for patients admitted from the emergency area. Calibration was excellent for risk lower than 60% but slightly underestimated observed risks above this level.

The American APACHE III equation fit well when applied to Spanish critical patients but with limitations. Discrepancies could be attributed to differences in case-mix and variations in practice style.