Abstract
Purpose
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.
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Acknowledgments
This study was supported through a research grant of Faculty of Medicine, Prince of Songkla University. We thank Alan Geater of the Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, for his comments on the statistical components of the paper.
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Khwannimit, B., Bhurayanontachai, R. The performance and customization of SAPS 3 admission score in a Thai medical intensive care unit. Intensive Care Med 36, 342–346 (2010). https://doi.org/10.1007/s00134-009-1629-7
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DOI: https://doi.org/10.1007/s00134-009-1629-7