Development and evaluation of predictive performance of “organ failure assessment by ratio score” to predict sepsis mortality in Indian intensive care unit patients: An observational study

Background and Aims: Sepsis is a common cause of mortality and morbidity in patients admitted to the intensive care unit (ICU), requiring reliable scoring systems to predict outcomes and guide management. Existing traditional scoring systems inadequately capture sepsis complexity. This study developed the Organ Failure Assessment by Ratio (OFAR) score to improve ICU mortality prediction in sepsis patients. Methods: This retrospective observational study was conducted in the ICUs of a tertiary care centre between January 2021 to December 2023 and included adult patients meeting Sepsis-3 criteria. Demographic data, ICU mortality, and six composite variables were collected: bilirubin-to-albumin ratio, pulse oximetric saturation to fraction of inspired oxygen ratio (SpO 2 /FiO 2 ratio), shock index, lactate-to-bicarbonate ratio, urea-to-estimated glomerular filtration rate ratio, and cumulative lung ultrasound score-to-platelet ratio. These variables were evaluated to develop and assess the predictive accuracy of OFAR score for ICU mortality. Results: The OFAR score showed greater discriminatory power with an area under the curve (AUC) of 0.78 than quick Sequential Organ Failure Assessment score (qSOFA) (AUC: 0.70) and Acute Physiology and Chronic Health Evaluation score II (APACHE II) (AUC: 0.73) and was comparable to Sequential Organ Failure Assessment score (SOFA) (AUC: 0.76). With a cut-off score of 51.6, OFAR score demonstrated a sensitivity of 73.7% and a specificity of 72.1%. Conclusion: The OFAR score provides higher predictive power for ICU mortality than qSOFA and APACHE II in our study population, raising its potential as an alternative risk stratification scoring system in sepsis patients. Additional external validation is required to confirm its generalisability across diverse populations.