SAPS 3 admission score: an external validation in a general intensive care population

ObjectivesTo validate the SAPS 3 admission score in an independent general intensive care case mix and to compare its performances with the APACHE II and the SAPS II scores.DesignCohort observational study.SettingA 26-bed general ICU from a Tertiary University Hospital.Patients and participantsEight hundred and fifty-one consecutive patients admitted to the ICU over an 8-month period. Of these patients, 49 were readmissions, leaving 802 patients for further analysis.InterventionNone.Measurements and resultsAPACHE II, SAPS II and SAPS 3 variables were prospectively collected; scores and their derived probability of death were calculated according to their original manuscript description. The discriminative power was assessed using the area under the ROC curve (AUROC) and calibration was verified with the Hosmer–Lemeshow goodness-of-fit test. The AUROC of the APACHE II model (AUROC = 0.823) was significantly lower than those of the SAPS II (AUROC = 0.850) and SAPS 3 models (AUROC = 0.854) (P = 0.038). The calibration of the APACHE II model (P = 0.037) and of the SAPS 3 global model (P = 0.035) appeared unsatisfactory. On the contrary, both SAPS II model and SAPS 3 model customised for Central and Western Europe had a good calibration. However, in our study case mix, SAPS II model tended to overestimate the probability of death.ConclusionIn this study, the SAPS 3 admission score and its prediction model customised for Central and Western Europe was more discriminative and better calibrated than APACHE II, but it was not significantly better than the SAPS II.

[1]  W. Knaus.  The APACHE III Prognostic System , 1992 .

[2]  W. Knaus,et al.  The APACHE III prognostic system. Risk prediction of hospital mortality for critically ill hospitalized adults. , 1991, Chest.

[3]  J. L. Gall,et al.  APACHE II--a severity of disease classification system. , 1986, Critical care medicine.

[4]  E. DeLong,et al.  Comparing the areas under two or more correlated receiver operating characteristic curves: a nonparametric approach. , 1988, Biometrics.

[5]  S. Lemeshow,et al.  A new Simplified Acute Physiology Score (SAPS II) based on a European/North American multicenter study. , 1993, JAMA.

[6]  J. Finn,et al.  Comparison of Acute Physiology and Chronic Health Evaluation (APACHE) II score with organ failure scores to predict hospital mortality , 2007, Anaesthesia.

[7]  S Lemeshow,et al.  A method for assessing the clinical performance and cost‐effectiveness of intensive care units: A multicenter inception cohort study , 1994, Critical care medicine.

[8]  M. Hiesmayr,et al.  Prognostic performance and customization of the SAPS II: results of a multicenter Austrian study , 1999, Intensive Care Medicine.

[9]  S. Lemeshow,et al.  Mortality Probability Models (MPM II) based on an international cohort of intensive care unit patients. , 1993, JAMA.

[10]  Sumithra J. Mandrekar,et al.  Statistical Methods in Diagnostic Medicine using SAS ® Software , 2005 .

[11]  K. Polderman,et al.  Inter-observer variability in APACHE II scoring: effect of strict guidelines and training , 2001, Intensive Care Medicine.

[12]  G. Apolone,et al.  The performance of SAPS II in a cohort of patients admitted to 99 Italian ICUs: Results from GiViTI , 1996, Intensive Care Medicine.

[13]  M. Capuzzo,et al.  Validation of severity scoring systems SAPS II and APACHE II in a single-center population , 2000, Intensive Care Medicine.

[14]  J H Kerr,et al.  Intensive Care Society's APACHE II study in Britain and Ireland--II: Outcome comparisons of intensive care units after adjustment for case mix by the American APACHE II method. , 1993, BMJ.

[15]  M. Mora,et al.  Mortality prediction in cardiac surgery patients: comparative performance of Parsonnet and general severity systems. , 1999, Circulation.

[16]  W. Knaus,et al.  An evaluation of outcome from intensive care in major medical centers. , 1987, Canadian critical care nursing journal.

[17]  V. Fidler,et al.  Evaluation of two outcome prediction models on an independent database. , 1998, Critical care medicine.

[18]  J. Hanley,et al.  A method of comparing the areas under receiver operating characteristic curves derived from the same cases. , 1983, Radiology.

[19]  J. Abadal,et al.  Simplified acute physiology score. , 1985, Critical Care Medicine.

[20]  Thomas Higgins,et al.  SAPS 3--From evaluation of the patient to evaluation of the intensive care unit. Part 2: Development of a prognostic model for hospital mortality at ICU admission. , 2005 .

[21]  R. Moreno,et al.  Outcome prediction in intensive care: results of a prospective, multicentre, Portuguese study , 1997, Intensive Care Medicine.