Sequential Organ Failure Assessment (SOFA)

The Sequential Organ Failure Assessment (SOFA) score is the standard criteria for sepsis. A SOFA score ≥ 2 in setting of infection strongly supports the diagnosis of sepsis.
Sepsis is defined as a life threatening organ dysfunction caused by a dysregulated host-response to infection.


SOFA variables:

  • PaO2/FiO2 ratio
  • Bilirubin
  • Platelet count
  • Serum creatinine or urine output
  • Mean arterial pressure (MAP)
  • Glasgow Coma Scale (GCS) score
  • Administration of vasopressors and dose rate


About this calculator

The Sequential Organ Failure Assessment (SOFA) is a morbidity severity score and mortality estimation tool developed from a large sample of ICU patients throughout the world. Unlike other scoring systems, such as the SAPS II and APACHE II systems, the SOFA was designed to focus on organ dysfunction and morbidity, with less of an emphasis on mortality prediction. The authors designed the system with an emphasis on bedside applicability and simplicity, using widely available variables.


Study Variables

The SOFA score is made of 6 variables, each representing an organ system. Each organ system is assigned a point value from 0 (normal) to 4 (high degree of dysfunction/failure). The worst physiological variables were collected serially every 24 hours of a patient's ICU admission. The "worst" measurement was defined as the measure that correlated to the highest number of points. The SOFA score ranges from 0 to 24.


Correlation of Total Score and Hospital Mortality

Maximum SOFA Score Mortality
0 to 6 < 10%
7 to 9 15 - 20%
10 to 12 40 - 50%
13 to 14 50 - 60%
15 > 80%
15 to 24 > 90%