Under Sepsis-3 (2016), sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Organ dysfunction is identified by an acute increase of ≥ 2 points in the SOFA score. A baseline SOFA of 0 is assumed for patients not known to have pre-existing organ dysfunction.

SOFA 0–1: mortality <3%. SOFA 2–6: mortality ~10–20%. SOFA 7–12: mortality ~30–50%. SOFA ≥13: mortality >50%. Serial SOFA measurements (trends) are often more informative than a single value — an increasing SOFA over 48-96 hours is strongly associated with mortality.

In ICU patients, SOFA is typically calculated at admission and every 24 hours. Serial assessment is valuable because the trend (increasing vs. decreasing) is a strong predictor of outcome. An increasing SOFA over 48 hours is associated with mortality rates up to 50%.