Comparison of the performance of SAPS II, SAPS 3, APACHE II, and their customized prognostic models in a surgical intensive care unit.
BACKGROUND
The Simplified Acute Physiology Score (SAPS) 3 has recently been developed, but not yet validated in surgical intensive care unit (ICU) patients. We compared the performance of SAPS 3 with SAPS II and the Acute Physiology and Chronic Health Evaluation (APACHE) II score in surgical ICU patients.


METHODS
Prospectively collected data from all patients admitted to a German university hospital postoperative ICU between August 2004 and December 2005 were analysed. The probability of ICU mortality was calculated for SAPS II, APACHE II, adjusted APACHE II (adj-APACHE II), SAPS 3, and SAPS 3 customized for Europe [C-SAPS3 (Eu)] using standard formulas. To improve calibration of the prognostic models, a first-level customization was performed, using logistic regression on the original scores, and the corresponding probability of ICU death was calculated for the customized scores (C-SAPS II, C-SAPS 3, and C-APACHE II).


RESULTS
The study included 1851 patients. Hospital mortality was 9%. Hosmer and Lemeshow statistics showed poor calibration for SAPS II, APACHE II, adj-APACHE II, SAPS 3, and C-SAPS 3 (Eu), but good calibration for C-SAPS II, C-APACHE II, and C-SAPS 3. Discrimination was generally good for all models [area under the receiver operating characteristic curve ranged from 0.78 (C-APACHE II) to 0.89 (C-SAPS 3)]. The C-SAPS 3 score appeared to have the best calibration curve on visual inspection.


CONCLUSIONS
In this group of surgical ICU patients, the performance of SAPS 3 was similar to that of APACHE II and SAPS II. Customization improved the calibration of all prognostic models.
Sakr
Y
Y
Department of Anaesthesiology and Intensive Care, Friedrich-Schiller-University Hospital, Erlanger Allee 103, 07743 Jena, Germany.
Krauss
C
C
Amaral
A C K B
AC
Réa-Neto
A
A
Specht
M
M
Reinhart
K
K
Marx
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003422:Critical Care / Q000379:methods; D004812:Epidemiologic Methods; D005260:Female; D005858:Germany; D006305:Health Status Indicators; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods*; D011379:Prognosis; D016896:Treatment Outcome; D055815:Young Adult