Critical Care
qSOFA Score
Quick bedside flag for poor outcome in suspected infection.
Education and reference only. Not a substitute for clinical judgement, local policy or product labelling. Always verify before clinical use. Values are calculated in your browser and never stored.
Background
The quick Sequential Organ Failure Assessment (qSOFA) is a simple bedside tool to identify patients with suspected infection who are at higher risk of a poor outcome, particularly outside the intensive care unit. It was introduced as part of the Sepsis-3 definitions to give a rapid, lab-free screen. One point is given for each of: respiratory rate ≥22/min, altered mentation (GCS <15) and systolic blood pressure ≤100 mmHg — a maximum of 3.
Interpreting the result
A qSOFA of 0–1 is regarded as lower risk, while a score of ≥2 is associated with markedly worse outcomes in patients with suspected infection. A score of ≥2 should prompt assessment for sepsis, closer monitoring and consideration of escalation. qSOFA is a prognostic flag, not a diagnostic test: it neither rules sepsis in nor out, and a low score does not exclude serious illness.
Advice
A qSOFA ≥2 is associated with worse outcomes in suspected infection and should prompt assessment for sepsis and consideration of escalation. It is a flag, not a diagnosis.
Worked example
A patient with suspected pneumonia has a respiratory rate of 24/min and a systolic blood pressure of 95 mmHg but is fully alert: Respiratory rate (1) + Systolic BP (1) = 2. This crosses the threshold and should prompt assessment for sepsis and consideration of escalation.
Pearls / pitfalls
- qSOFA has relatively low sensitivity — a score below 2 does not exclude sepsis, so clinical concern should always override a reassuring score.
- It is a prognostic flag for poor outcome, not a diagnostic criterion for sepsis itself.
- In the UK, NEWS2 is generally the preferred bedside escalation tool; qSOFA can complement but should not replace local sepsis screening.
- Altered mentation means any GCS below 15, including subtle new confusion, not only deep coma.
Evidence & validation
qSOFA was derived and described in the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3, Singer et al.). Subsequent studies show good specificity but limited sensitivity, so it is used as a flag alongside clinical judgement and other screening tools such as NEWS2.
Frequently asked questions
What does a qSOFA of 2 or more mean?
It identifies a patient with suspected infection who is at higher risk of a poor outcome. It should prompt assessment for sepsis, closer monitoring and consideration of escalation, but it is not a diagnosis of sepsis.
Does a low qSOFA rule out sepsis?
No. qSOFA has limited sensitivity, so a score below 2 does not exclude sepsis. Ongoing clinical concern should always take priority over a reassuring score.
How does qSOFA differ from the full SOFA score?
The full SOFA score uses laboratory and physiological data across several organ systems to quantify organ dysfunction. qSOFA is a rapid bedside subset requiring no tests, used only to flag risk.
Should I use qSOFA or NEWS2?
In UK practice NEWS2 is the standard bedside escalation score. qSOFA can complement it in suspected infection but is not a replacement for local sepsis screening.
Where is qSOFA most useful?
It was designed mainly for use outside the intensive care unit, such as on general wards and in the emergency department, to quickly identify higher-risk patients with suspected infection.
References
- Singer M, Deutschman CS, Seymour CW, et al. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315(8):801–810.
- NICE NG51: Sepsis: recognition, diagnosis and early management. 2016 (updated 2024).
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