Comparison of Sequential Organ Failure Assessment Score and Sequential Organ Failure Assessment Score with pH in Outcome Prediction among ICU Patients: A Prospective Observational Study

Abstract

Aim: To examine if sequential organ failure assessment (SOFA) alone or SOFA in combination with pH is a better prognosis and mortality indicator. Materials and methods: We conducted a prospective observational study in a total of sixty patients. The mortality of patients was predicted on the basis of a SOFA score alone or SOFA score in combination with pH, and the prediction by both was compared to the actual outcome. The comparison was based on the “standardized mortality ratio” and the “area under the receiver operating characteristic curve (AUROC).” Result: At the time of admission, both the scores (SOFA and SOFA with pH) were equally effective in predicting mortality. At 48 hours, SOFA with pH proves to be slightly better in mortality prediction than SOFA score alone. The discriminative power of both the scores was assessed by calculating AUROC. AUROC of the SOFA score was better than that of SOFA with pH at admission and at 48 hours, but statistically, both had the same level of discrimination, i.e., excellent. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were the same for both the scores at admission, but all parameters except specificity were better for SOFA with pH at 48 hours. Specificity was the same for both even at 48 hours. Conclusion: At the time of admission, SOFA score and SOFA with pH were equally effective in outcome prediction, but after 48 hours, SOFA with pH proves to be better than the SOFA score alone. The power of discrimination is the same for both the scores at admission and at 48 hours.