What the qSOFA score is
The quick Sequential Organ Failure Assessment (qSOFA) is a rapid, bedside risk-stratification tool introduced with the 2016 Sepsis-3 definitions. It is designed to be applied quickly, without laboratory tests, to patients with suspected infection in order to flag those at increased risk of death or prolonged critical-care stay. A high score is a prompt to act, not a diagnosis.
How it works
qSOFA awards one point for each of three criteria:
- Altered mentation — a Glasgow Coma Scale score below 15, or any new alteration in mental state.
- Respiratory rate ≥22 breaths per minute.
- Systolic blood pressure ≤100 mmHg.
The points are summed to give a total of 0 to 3. A total of ≥2 identifies a patient at substantially higher risk of a poor outcome and should trigger closer monitoring, a search for organ dysfunction (for example with the full SOFA score), escalation of care, and initiation of the sepsis management bundle where infection is suspected.
Interpreting the score
| Score | Implication |
|---|---|
| 0 | Low risk — standard monitoring unless clinical concern overrides |
| 1 | Monitor closely; consider whether a source of infection needs investigation |
| 2–3 | Higher risk of deterioration — assess for organ dysfunction, escalate care, initiate sepsis pathway |
A score of 2 or 3 is a prompt for action, not a diagnosis. Clinical judgement, the full SOFA score, and laboratory data are essential next steps.
qSOFA versus the full SOFA score
The full SOFA (Sequential Organ Failure Assessment) score grades dysfunction across six organ systems — respiratory, coagulation, liver, cardiovascular, neurological (GCS), and renal — using laboratory values and vasopressor doses. It is the gold standard for assessing organ dysfunction severity in the ICU and for the formal Sepsis-3 definition (sepsis = life-threatening organ dysfunction with SOFA ≥2 above baseline).
qSOFA was designed for use outside the ICU, in emergency departments, hospital wards, and pre-hospital settings, where laboratory results may not be immediately available and speed matters. It uses only three clinical observations that can be obtained in under a minute.
The trade-off is sensitivity. qSOFA misses some patients who are deteriorating but have not yet shown all three signs. In NHS settings, NEWS2 (National Early Warning Score 2) is the primary deterioration screening tool and is more sensitive than qSOFA across a general ward population. qSOFA is most useful as a focused, quick adjunct when infection is specifically suspected.
Clinical context
This calculator is a reference tool for educational and clinical support purposes. It does not replace clinical judgement, senior review, or local sepsis protocols. A qSOFA score of 0 or 1 does not exclude sepsis; a score of 2 or 3 does not confirm it. Always use the result alongside the full clinical picture, vital sign trends, history, and available investigations. When in doubt, escalate early — sepsis can progress rapidly and outcomes are strongly time-dependent.
Tips and notes
qSOFA is deliberately simple so it can be applied in seconds at the bedside. Because it is specific but relatively insensitive, a score below 2 does not rule out sepsis — clinical concern always overrides the number. In NHS settings, NEWS2 remains the primary deterioration tool, and qSOFA is best used as a focused adjunct when infection is suspected. Always combine the score with the full clinical picture, local sepsis protocols, and senior review.