An Immediate Mortality Prediction Score That is Robust to Missing Data

Objective: To develop an illness severity score that predicts short-term mortality, based on a small number of readily available measurements, and overcomes limitations of the SOFA score, for use in research involving large-scale electronic health records. Design: Retrospective analysis of electronic records for 37,739 adult inpatients. Setting: A single tertiary care hospital system from 2016-2022. Patients: 37,739 adult ICU patients. Interventions: IMPS was developed using logistic regression with the 6 SOFA components, age, sex and missingness indicators as predictors, and 10-day mortality as the outcome. This was compared with SOFA with median imputation. Measurements and Main Results: Discrimination was evaluated by AUROC, calibration by comparing predicted and observed mortality. IMPS showed excellent discrimination (AUROC 0.80) and calibration. It outperformed SOFA alone (AUROC 0.70) and with age/sex (0.74). Conclusions: By retaining continuous data, adding age, allowing for missingness, and optimizing weights based on empirical mortality association, IMPS achieved substantially better mortality prediction than the original SOFA.