qSOFA Calculator

qSOFA criteria

Each criterion scores 1 point. The total ranges from 0 to 3. No blood tests are required, which is why qSOFA is usable anywhere observations can be taken.

qSOFA is a risk-stratification prompt, not a diagnostic test for sepsis. It was derived to identify patients with suspected infection who are likely to have a prolonged ICU stay or die in hospital.

qSOFA score interpretation

Interpret the score alongside the suspicion of infection and the overall clinical picture.

• 0Low score

  A low qSOFA score does not rule out sepsis. Clinical judgement remains essential — continue to assess and re-score if the patient changes.

• 1One criterion present

  Monitor closely and reassess if the clinical condition changes.

• 2–3High risk of poor outcome

  Consider sepsis and the need for intensive monitoring. Escalate, investigate the source, and follow local sepsis pathways.

How to calculate qSOFA

1. 1Confirm that infection is suspected — qSOFA is only meaningful in that context.
2. 2Measure the respiratory rate over a full minute and score 1 if it is 22 or more.
3. 3Assess mentation and score 1 for any new confusion or a Glasgow Coma Scale below 15.
4. 4Measure the systolic blood pressure and score 1 if it is 100 mmHg or less.
5. 5Add the points and act on the total together with your local sepsis screening tool.

Common pitfalls

• Using qSOFA as a sepsis rule-out. Its sensitivity is limited, and a score of 0 in an unwell patient with suspected infection should not delay treatment.
• Using qSOFA in place of a full sepsis screening tool. In UK practice NEWS2 plus a sepsis screening tool is the usual trigger; qSOFA is a supplementary prompt.
• Scoring an estimated respiratory rate. Respiratory rate is the single most predictive observation and needs to be counted properly.
• Attributing altered mentation to a chronic baseline without checking a collateral history — new confusion is what counts.

Frequently asked questions

When should qSOFA be used?

qSOFA is used to rapidly identify patients with suspected infection who are at higher risk of poor outcomes. It requires no laboratory tests and can be used at the bedside, in the community, or pre-hospital. It should not delay treatment of suspected sepsis.

How do you interpret the qSOFA score?

A score of 0 does not rule out sepsis and clinical judgement remains essential. A score of 1 means one criterion is present - monitor closely and reassess if the clinical condition changes. A score of 2 or more indicates high risk of poor outcome - consider sepsis and the need for intensive monitoring.

What are the three qSOFA criteria?

Respiratory rate of 22 breaths per minute or more, altered mentation (Glasgow Coma Scale below 15 or new confusion), and systolic blood pressure of 100 mmHg or less. Each scores 1 point for a maximum of 3.

Is qSOFA better than NEWS2 for detecting sepsis?

They do different jobs. NEWS2 is a general deterioration score used across the NHS and is more sensitive for identifying unwell patients, while qSOFA is a short prognostic prompt for patients in whom infection is already suspected. UK practice generally uses NEWS2 with a sepsis screening tool, with qSOFA as an adjunct.

Does qSOFA replace SIRS criteria?

The Sepsis-3 definitions moved away from SIRS criteria for defining sepsis and introduced qSOFA as a bedside prompt for patients likely to have poor outcomes. Many organisations still use SIRS-based screening locally, so follow your own sepsis pathway.

Sources and further reading

• Sepsis: recognition, diagnosis and early management (NG51) — NICE
• Surviving Sepsis Campaign guidelines — Society of Critical Care Medicine

This page is reference information for registered healthcare professionals. It is not medical advice and does not replace clinical judgement, local policy, or the current version of the source guidance. Always verify scores and thresholds against your own organisation's pathway before acting on them.