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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References
Le Gall JR (2005) The use of severity scores in the intensive care unit. Intensive Care Med 31:1618–1623
Moreno R, Morais P (1997) Outcome prediction in intensive care: results of a prospective, multicentre, Portuguese study. Intensive Care Med 23:177–186
Patel PA, Grant BJ (1999) Application of mortality prediction systems to individual intensive care units. Intensive Care Med 25:977–982
Arabi Y, Haddad S, Goraj R, Al-Shimemeri A, Al-Malik S (2002) Assessment of performance of four mortality prediction systems in a Saudi Arabian intensive care unit. Crit Care 6:166–174
Beck DH, Smith GB, Pappachan JV, Millar B (2003) External validation of the SAPS II, APACHE II and APACHE III prognostic models in South England: a multicentre study. Intensive Care Med 29:249–256
Khwannimit B, Geater A (2007) A comparison of APACHE II and SAPS II scoring systems in predicting hospital mortality in Thai adult intensive care units. J Med Assoc Thai 90:643–652
Metnitz PG, Moreno RP, Almeida E, Jordan B, Bauer P, Campos RA, Iapichino G, Edbrooke D, Capuzzo M, Le Gall JR (2005) SAPS 3—from evaluation of the patient to evaluation of the intensive care unit. Part 1: objectives, methods and cohort description. Intensive Care Med 31:1336–1344
Moreno RP, Metnitz PG, Almeida E, Jordan B, Bauer P, Campos RA, Iapichino G, Edbrooke D, Capuzzo M, Le Gall JR (2005) 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. Intensive Care Med 31:1345–1355
Soares M, Salluh JI (2006) Validation of the SAPS 3 admission prognostic model in patients with cancer in need of intensive care. Intensive Care Med 32:1839–1844
Ledoux D, Canivet JL, Preiser JC, Lefrancq J, Damas P (2008) SAPS 3 admission score: an external validation in a general intensive care population. Intensive Care Med 34:1873–1877
Duke GJ, Piercy M, DiGiantomasso D, Green JV (2008) Comparison of intensive care outcome prediction models based on admission scores with those based on 24-hour data. Anaesth Intensive Care 36:845–849
Sakr Y, Krauss C, Amaral AC, Rea-Neto A, Specht M, Reinhart K, Marx G (2008) Comparison of the performance of SAPS II, SAPS 3, APACHE II, and their customized prognostic models in a surgical intensive care unit. Br J Anaesth 101:798–803
Metnitz B, Schaden E, Moreno R, Le Gall JR, Bauer P, Metnitz PG (2009) Austrian validation and customization of the SAPS 3 admission score. Intensive Care Med 35:616–622
Khwannimit B (2008) Validation of the LOD score compared with APACHE II score in prediction of the hospital outcome in critically ill patients. Southeast Asian J Trop Med Public Health 39:138–145
Hanley JA, McNeil BJ (1982) The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology 143:29–36
Lemeshow S, Hosmer DW Jr (1982) A review of goodness of fit statistics for use in the development of logistic regression models. Am J Epidemiol 115:92–106
Rapoport J, Teres D, Lemeshow S, Gehlbach S (1994) A method for assessing the clinical performance and cost-effectiveness of intensive care units: a multicenter inception cohort study. Crit Care Med 22:1385–1391
Moreno R, Apolone G (1997) Impact of different customization strategies in the performance of a general severity score. Crit Care Med 25:2001–2008
Aegerter P, Boumendil A, Retbi A, Minvielle E, Dervaux B, Guidet B (2005) SAPS II revisited. Intensive Care Med 31:416–423
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