SOFA Score
Calculate the SOFA (Sequential Organ Failure Assessment) score for critically ill patients to quantify organ dysfunction across six systems. Free online SOFA calculator with mortality risk assessment.
About This Calculator
About the SOFA Score
The SOFA (Sequential Organ Failure Assessment) Score Calculator helps healthcare professionals quantify the degree of organ dysfunction in critically ill patients admitted to intensive care units (ICUs). Developed in 1994 by the European Society of Intensive Care Medicine (ESICM) under the leadership of Dr. Jean-Louis Vincent, the SOFA score evaluates six organ systems — respiratory, coagulation, liver, cardiovascular, central nervous system, and renal — each scored from 0 (normal function) to 4 (severe dysfunction) for a total possible score of 24. The score was originally named Sepsis-Related Organ Failure Assessment but was later renamed to reflect its broader applicability to all critically ill patients.
Each organ system is assessed using objective clinical or laboratory parameters: the respiratory component uses the PaO₂/FiO₂ ratio; coagulation uses platelet count; liver function is evaluated by serum bilirubin; the cardiovascular system is assessed by mean arterial pressure and vasopressor requirements; the central nervous system is evaluated using the Glasgow Coma Scale; and renal function is assessed by serum creatinine or urine output. The SOFA score is typically calculated daily throughout the ICU stay, as serial measurements provide valuable prognostic information — an increase in score during the first 48 hours of admission correlates with a mortality rate of at least 50%.
The SOFA score serves multiple purposes in critical care: it provides a standardized, reproducible method for describing organ dysfunction; it enables risk stratification and prognostic assessment; it facilitates communication among healthcare providers; and it is widely used as an endpoint in clinical trials of sepsis and critical illness interventions. The score has been validated across diverse patient populations and healthcare settings worldwide, making it one of the most widely used severity scores in intensive care medicine alongside APACHE II and SAPS II.
Regional Notes
The SOFA score is used in ICUs worldwide, including the United States (Surviving Sepsis Campaign guidelines), the United Kingdom (NICE guidelines for sepsis), and India (ISCCM sepsis protocols). The scoring criteria and mortality data are consistent across regions, though local laboratory reference ranges and vasopressor protocols may vary. Healthcare professionals should always interpret results within the context of their clinical setting and local practices.
This calculator is for educational and reference purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional for clinical decision-making.
Frequently Asked Questions
What is the SOFA score used for?
The SOFA (Sequential Organ Failure Assessment) score is used in ICUs to quantify the degree of organ dysfunction across six organ systems — respiratory, coagulation, liver, cardiovascular, central nervous system, and renal. Each system is scored from 0 to 4 based on clinical and laboratory parameters, with a total score ranging from 0 to 24. It helps clinicians assess the severity of illness, monitor response to treatment, and predict mortality risk in critically ill patients, particularly those with sepsis.
How is the SOFA score calculated?
The SOFA score is calculated by assigning 0 to 4 points for each of six organ systems: Respiratory (PaO2/FiO2 ratio), Coagulation (platelet count), Liver (bilirubin), Cardiovascular (mean arterial pressure or vasopressor requirement), Central Nervous System (Glasgow Coma Scale), and Renal (creatinine or urine output). The scores for all six systems are summed to produce the total SOFA score out of 24. Higher scores indicate more severe organ dysfunction.
What does a SOFA score of 0 mean?
A SOFA score of 0 indicates no organ dysfunction across all six assessed organ systems. This is the best possible score and suggests the patient has normal organ function. It corresponds to the lowest mortality risk (0% by both initial and highest score mortality tables).
What is the mortality rate associated with different SOFA scores?
Based on the study by Ferreira et al. (2001), mortality increases with higher SOFA scores. For an initial score of 0-1, mortality is 0%; 2-3 scores have 4% mortality; 4-5 scores have 20%; 6-7 scores have 22%; 8-9 scores have 33%; 10-11 scores have 50%; 12-14 scores have 95%; and above 14 scores have 95%. The highest score during ICU stay is a stronger predictor: 0-1 scores have 0%, 2-3 have 7%, and above 14 have 90% mortality.
What is the difference between SOFA and qSOFA?
qSOFA (quick SOFA) is a simplified bedside screening tool that uses only three criteria — altered mental status, respiratory rate ≥22/min, and systolic blood pressure ≤100 mmHg — scored 0-3. It is used outside the ICU to rapidly identify patients at risk of poor outcomes from suspected infection. The full SOFA score requires laboratory values and is more comprehensive, scoring six organ systems from 0-24, and is typically used in ICU settings for detailed organ dysfunction assessment.
Who developed the SOFA score?
The SOFA score was developed in 1994 by a working group of the European Society of Intensive Care Medicine (ESICM), led by Dr. Jean-Louis Vincent. It was initially called the Sepsis-Related Organ Failure Assessment, but the name was changed to Sequential Organ Failure Assessment since the score is not specific to sepsis and can be applied to all critically ill patients.
How often should the SOFA score be measured?
The SOFA score is typically assessed daily during the ICU stay. An increase of 1-2 points in the first 48 hours of admission correlates with a 50% or higher mortality rate, making serial assessment important. The mean and highest SOFA scores during ICU admission are stronger predictors of outcome than the initial score alone. The trend of scores over time provides valuable prognostic information.
Is this calculator a substitute for professional medical assessment?
No. This calculator is for educational and reference purposes only and is not a substitute for professional medical assessment. The SOFA score should always be used by qualified healthcare professionals as part of a comprehensive clinical evaluation of a critically ill patient. Clinical judgment should accompany any scoring system.