Year: 2025 | Month: November | Volume: 15 | Issue: 11 | Pages: 192-202
DOI: https://doi.org/10.52403/ijhsr.20251124
Comparison of APACHE II and APACHE IV Scores in Predicting Mortality in the Surgical ICU (SICU) of a Tertiary Care Hospital - A Prospective Study
Prashanta Swami Pujar1, Pavithra P2, Sachin3, Prajwal RK4
1Assistant Professor, Department of General Surgery, Hassan Institute of Medical Sciences, Hassan, India.
2Assistant Professor, Department of Community Medicine, Hassan Institute of Medical Sciences, Hassan, India.
3Assistant Professor, Department of General Surgery, Hassan Institute of Medical Sciences, Hassan, India.
4Assistant Professor, Department of General Surgery, Hassan Institute of Medical Sciences, Hassan, India.
Hassan Institute of Medical Sciences, Hassan, Rajiv Gandhi University of Health Sciences
(RGUHS-Bengaluru), India
Corresponding Author: Dr Prashanta Swami Pujar
ABSTRACT
Background: The postoperative surgical outcome in terms of serious complications and mortality remains a major challenge for operating surgeons. Severity scoring systems, such as APACHE II and APACHE IV, provide objective assessment of mortality risk and outcomes in critically ill patients. Most studies focus on medical ICUs, and calibration and discrimination of these scores vary across populations, highlighting the need for evaluation in surgical ICU patients.
Objectives: To evaluate APACHE II and APACHE IV in predicting mortality among Surgical ICU (SICU) patients and compare their accuracy in discrimination and calibration.
Methods: This prospective study included 50 SICU patients admitted to a tertiary hospital in Hassan in 2025. APACHE II and IV scores were calculated within 24 hours of ICU admission. Mortality prediction, discrimination, calibration and standardized mortality ratio (SMR) were assessed.
Results: Mean age was 49.5 ± 12.4 years; 62% were male; mortality was 20%. Mean APACHE II and IV scores were 18.1 ± 12.96 and 65.2 ± 34.33. SMRs were 0.505 and 0.769, indicating lower-than-expected mortality. APACHE IV showed slightly better discrimination (AUC 0.994) than APACHE II (AUC 0.975). Both scores had excellent calibration (Hosmer–Lemeshow χ²: II = 2.38, p = 0.969; IV = 5.26, p = 0.729). Logistic regression showed each unit increase in APACHE II increased odds of death by 54%, while APACHE IV increased odds by 32%.
Conclusion: Both APACHE II and IV reliably predict mortality in SICU patients, with APACHE IV showing slightly superior discrimination, supporting their use for risk stratification and clinical decisions.
Key words: APACHE II, APACHE IV, Surgical ICU, Mortality Prediction, Calibration, Discrimination.