Prognostic performance and customization of the SAPS II: results of a multicenter Austrian study. Simplified Acute Physiology Score.
OBJECTIVE
To evaluate the prognostic performance of the original Simplified Acute Physiology Score (SAPS) II in Austrian intensive care patients and to evaluate the impact of customization.


METHODS
Analysis of the database of a multicenter study.


METHODS
Nine adult medical, surgical, and mixed intensive care units (ICUs) in Austria.


METHODS
A total of 1733 patients consecutively admitted to the ICUs.


RESULTS
The database included admission data, SAPS II, length of stay, and hospital mortality. The Hosmer-Lemeshow goodness-of-fit test for the SAPS II showed a lack of uniformity of fit (H = 89.1, 10 df, p < 0.0001; C = 91.8, 10 df, p < 0.0001). Subgroup analysis showed good performance in patients with cardiovascular (medical and surgical) diseases as the primary reasons for admission. A new predictive equation was derived by means of the logistic regression. Goodness-of-fit was excellent for the customized model (SAPS IIAM) (H = 11.2, 9 df, p = 0.33, C = 11.6, 9 df, p = 0.24). The mean standardized mortality ratio (SMR) changed from 0.81 +/- 0.26 to 0.93 +/- 0.29 with customization.


CONCLUSIONS
SAPS II was not well calibrated when applied to all patients. However, it performed well for patients with cardiovascular diseases as the primary reason for admission and may thus be applied to these patients. Standardized mortality ratios that are calculated from scoring systems without known calibration must be viewed with skepticism.
Metnitz
P G
PG
Department of Anesthesiology and General Intensive Care, University Hospital of Vienna, Austria. metnitz@akh-wien.ac.at
Valentin
A
A
Vesely
H
H
Alberti
C
C
Lang
T
T
Lenz
K
K
Steltzer
H
H
Hiesmayr
M
M
D001317:Austria; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D007902:Length of Stay; D016015:Logistic Models; D008875:Middle Aged; D015233:Models, Statistical; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D012720:Severity of Illness Index