Background: 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.
Patients and method: 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.
Results: 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.
Conclusions: 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.