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VOLUME 28 , ISSUE 4 ( April, 2024 ) > List of Articles

Original Article

Comparative Predictive Accuracies of the Simplified Mortality Score for the Intensive Care Unit, Sepsis Severity Score, and Standard Severity Scores for 90-day Mortality in Sepsis Patients

Natthaka Sathaporn, Bodin Khwannimit

Keywords : Intensive care unit, Mortality, Risk prediction, Severity score

Citation Information : Sathaporn N, Khwannimit B. Comparative Predictive Accuracies of the Simplified Mortality Score for the Intensive Care Unit, Sepsis Severity Score, and Standard Severity Scores for 90-day Mortality in Sepsis Patients. Indian J Crit Care Med 2024; 28 (4):343-348.

DOI: 10.5005/jp-journals-10071-24673

License: CC BY-NC 4.0

Published Online: 30-03-2024

Copyright Statement:  Copyright © 2024; The Author(s).


Background: The standard severity scores were used for predicting hospital mortality of intensive care unit (ICU) patients. Recently, the new predictive score, Simplified Mortality Score for the ICU (SMS–ICU), was developed for predicting 90-day mortality. Objective: To validate the ability of the SMS–ICU and compare with sepsis severity score (SSS) and original severity scores for predicting 90-day mortality in sepsis patients. Method: An analysis of retrospective data was conducted in the ICU of a university teaching hospital. Also, 90-day mortality was used for the primary outcome. Results: A total of 1,161 patients with sepsis were included. The 90-day mortality was 42.4%. The SMS–ICU presented the area under the receiver operating characteristic curve (AUROC) of 0.71, whereas the SSS had significantly higher AUROC than that of the SMS–ICU (AUROC 0.876, p < 0.001). The acute physiology and chronic health evaluation (APACHE) II and IV, and the simplified acute physiology scores (SAPS) II demonstrated good discrimination, with an AUROC above 0.90. The SMS–ICU provides poor calibration for 90-day mortality prediction, similar to the SSS and other standard severity scores. Furthermore, 90-day mortality was underestimated by the SMS–ICU, which had a standardized mortality ratio (SMR) of 1.36. The overall performance by Brier score demonstrated that the SMS–ICU was inferior to the SSS (0.222 and 0.169, respectively). Also, SAPS II presented the best overall performance with a Brier score of 0.092. Conclusion: The SMS–ICU indicated lower performance compared to the SSS, standard severity scores. Consequently, modifications are required to enhance the performance of the SMS–ICU.

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