Validity of APACHE II and SAPS II scores as predictors of early global mortality at 3 months from sepsis

Abstract

Background: Acute Physiology and Chronic Health Evaluation (APACHE) II and Simplified Acute Physiology Score (SAPS) II have become a necessary tool to describe intensive care unit (ICU) patients and to predict differences in mortality. Both are calculated in the first 24 hours of hospitalization, in which higher levels correspond to more serious diseases and a higher risk of death. Sepsis is a major cause of morbidity in ICU, it is estimated that about half of the patients have a healthcare-associated infection and are, therefore, at a higher risk of death. This study aims to determine the comparative efficacy of different scoring system (APACHE II and SAPS II scores) in assessing the prognosis of critically ill patients that were admitted to the ICU by sepsis in a tertiary hospital and compare them for prediction of the outcome in these patients in early mortality (up to 3 months).

Methods: We performed a retrospective review of five hundred and thirty three patients admitted to the ICU from January 2018 to December 2019. We included all patients (medical or surgical patients) over the age 16 years old, and we selected those with the first diagnosis of “sepsis”. Patient selection and data collection were obtained through medical records. Predicted mortality was calculated using APACHE II and SAPS II and also the early mortality. Group comparisons between survivors and non-survivors from sepsis were performed using
the Student-T test to compare continuous with categorical variables and chi square test for categorical variables. Pearson’s correlation was used to compare two continuous variables Statistical analysis was performed using SPSS software version 27.0 (IBM, Armonk, NY, USA).

Results: Out of 533 patients, 71 had sepsis (13%). Of these 71 patients, 36 (50.7%) die during the 3 month follow-up. Average APACHE II and SAPS II scores in all patients were 23.5 ± 8.1 (p=0.02) and 52.9 ± 17.7 respectively, and they were significantly different between survivors and non-survivors. A statistically significant positive correlation was established between the values of SAPS II and APACHE II (r=0.76; p<0.01). By the examination of validity and classification accuracy by ROC curve, we conclude that: SAPS II had AUC > 0.662 and APACHE II had AUC > 0.639. Both can predict the risk of mortality in these patients, but SAPS II seems to be slightly more accurate. We also observed that elderly patients were expected to have a worse prognosis. The average age of survivors was 64.5 ± 13.8 years and for non-survivors 75.2 ± 8.8 years (p<0.01).
Conclusion: Both APACHE and SAPS II are accurate tools to describe and predict mortality caused by sepsis. There was no significant difference in the clinical values of SAPS II and APACHE II and taking in consideration the high correlation between both, only one, could be enough to make a mortality prediction.

© 2021 Galicia Clínica.