Highlight
– SOFA-2 updates the Sequential Organ Failure Assessment with contemporary organ-support variables and revised thresholds, validated across >3.3 million ICU admissions from 9 countries.
– SOFA-2 showed modestly better discrimination for ICU mortality than the original SOFA (AUROC 0.79 vs 0.77) and maintained predictive validity over ICU days 1–7.
– Gastrointestinal and immune dysfunction were not included due to insufficient data and low content validity, underscoring measurement challenges for some organ systems.
