A Comparison of APACHE II and SAPS II Scoring Systems in Predicting Hospital Mortality in Thai Adult Intensive Care Units
Bodin Khwannimit MD*, Alan Geater PhD**
Affiliation : * Division of Critical Care, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla ** Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla
Objective : To assess the performance of Acute Physiology and Chronic Health Evaluation II (APACHE II) and
Simplified Acute Physiology Score II (SAPS II) in Thai critically ill patients.
Materials and Methods : Prospective observational cohort study conducted between July 1, 2004 and October
31, 2005 in the Intensive Care Unit (ICU) of Songklanagarind Hospital, an 800-beds tertiary referral univer-
sity teaching hospital.
Results : One thousand three hundred sixteen patients were enrolled. There were 310 deaths (23.6%) at
hospital discharge. APACHE II and SAPS II predicted hospital mortality 30.5 + 28.2 and 30.5 + 29.8 respec-
tively. Both models showed excellent discrimination. The discrimination of APACHE II was better than SAPS
II (0.911 and 0.888, p < 0.001). However, both systems presented a poor calibration. The Hosmer-Lemeshow
goodness-of-fit H and C statistics were 66.59 and 66.65 of APACHE II (p < 0.001) and 54.01 and 71.44 of SAPS
II (p < 0.001).
Conclusion : APACHE II provided better discrimination than SAPS II, but both models showed poor calibra-
tion in over predicting mortality in our ICU patients. Customized or new severity scoring systems should be
developed for critically ill patients in Thailand.
Keywords : Severity of illness, Intensive care, Mortality prediction, Acute Physiology and Chronic Health Evaluation (APACHE II), Simplified Acute Physiology Score (SAPS II)
