The performance and customization of SAPS 3 admission score in a Thai medical intensive care unit.
OBJECTIVE
The aim of this study was to evaluate the performance of Simplified Acute Physiology Score 3 (SAPS 3) admission scores, both the original and a customized version, in mixed medical critically ill patients.


METHODS
A prospective cohort study was conducted over a 2-year period in the medical intensive care unit (MICU) of a tertiary referral university teaching hospital in Thailand. The probability of hospital mortality of the original SAPS 3 was calculated using the general and customized Australasia version (SAPS 3-AUS). The patients were randomly divided into equal calibration and validation groups for customization.


RESULTS
A total of 1,873 patients were enrolled. The hospital mortality rate was 28.6%. The general equation of SAPS 3 had excellent discrimination with an area under the receiver operating characteristic curve of 0.933, but poor calibration with the Hosmer-Lemeshow goodness-of-fit H = 106.7 and C = 101.2 (P < 0.001), and it overestimated mortality with a standardized mortality ratio of 0.86 (95% confidence interval, 0.79-0.93). The calibration of SAPS 3-AUS was also poor. The customized SAPS 3 showed a good calibration of all patients in the validation group (H = 14, P = 0.17 and C = 11.3, P = 0.33) and all subgroups according to main diagnosis, age, gender and co-morbidities.


CONCLUSIONS
The SAPS 3 provided excellent discrimination but poor calibration in our MICU. A first level customization of the SAPS 3 improved the calibration and could be used to predict mortality and quality assessment in our ICU or other ICUs with a similar case mix.
Khwannimit
Bodin
B
Division of Critical Care, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand. kbordin@medicine.psu.ac.th
Bhurayanontachai
Rungsun
R
D000368:Aged; D015331:Cohort Studies; D016638:Critical Illness; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data*; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D013785:Thailand / Q000453:epidemiology