emergency & critical carescoring tool

qSOFA (Quick SOFA)

The qSOFA is a rapid bedside screening tool using three simple clinical criteria to identify adult patients with suspected infection who are at greater risk of poor outcomes. It requires no laboratory tests and can be performed in seconds.

inputs

Positive if ≤100 mmHg
mmHg
Positive if ≥22 breaths/min
breaths/min

✓ when to use

Use as a rapid bedside prompt in adult patients with suspected or confirmed infection, outside of the ICU, to identify those who may have or be developing sepsis-related organ dysfunction. Appropriate in ED triage, ward assessments, and pre-hospital settings. A qSOFA ≥2 should trigger urgent assessment for organ dysfunction and consideration of sepsis management pathways.

✗ when not to use

qSOFA is a screening prompt, not a diagnostic criterion for sepsis. Sepsis-3 defines sepsis as infection with organ dysfunction (SOFA increase ≥2), not by qSOFA score alone. A qSOFA of 0 or 1 does NOT rule out sepsis — it has moderate specificity but limited sensitivity. Do not use qSOFA to delay treatment in patients with clinical concern for sepsis. Not validated in paediatric populations. In ICU patients, use the full SOFA score directly.

clinical pearls

  • qSOFA is a screening prompt, not a diagnostic test. Think of it as a 'red flag' that should trigger further assessment — not as a definitive answer about whether sepsis is present.
  • The biggest pitfall with qSOFA is false reassurance. A qSOFA of 0 does not mean a patient is not septic. If clinical suspicion for infection with organ dysfunction is high, investigate and treat regardless of the qSOFA score.
  • In UK NHS practice, NEWS2 is the standard early warning tool and has better sensitivity for deterioration than qSOFA. qSOFA is most useful in resource-limited or pre-hospital settings where NEWS2 parameters are not all available.
  • qSOFA was validated for use outside the ICU. In ICU patients, organ dysfunction should be assessed using the full SOFA score, which incorporates laboratory values and vasopressor requirements.
  • The altered mentation criterion in qSOFA is defined as any GCS <15, which is deliberately broad. Even a GCS of 14 (mildly confused) counts. This is intentional — subtle changes in consciousness in an infected patient can herald rapid deterioration.

related tools

sofaFull SOFA score for organ dysfunction assessmentnews2UK standard early warning score — more sensitive than qSOFAcurb-65Pneumonia severity — common source of sepsis