How this instrument works
Quick SOFA, or qSOFA, checks three things: is the respiratory rate 22 breaths a minute or higher, is mentation altered from baseline, and is systolic blood pressure 100 mmHg or below. Each present criterion adds one point, for a total from 0 to 3. It exists alongside the full SOFA score — also on this site — which needs laboratory values like creatinine, bilirubin, and platelet count and is built for patients already in an ICU. qSOFA trades some of that precision for speed: three things a clinician can assess just by looking, listening, and taking a blood pressure, useful anywhere from an emergency department triage desk to a general ward.
The score comes from the Sepsis-3 consensus definitions, published in JAMA in 2016 by Singer, Deutschman, Seymour, and colleagues, alongside a companion derivation and validation study led by Seymour using data from over a million encounters. That work reframed sepsis as infection plus organ dysfunction, and proposed qSOFA as a fast way to flag patients outside the ICU whose infection might already be causing that dysfunction. A score of 2 or higher is the threshold the consensus statement associated with a meaningfully higher risk of prolonged ICU stay or death, and is generally read as a prompt for closer evaluation, not a diagnosis.
What qSOFA does not do is rule sepsis out. It was built to be a quick screen, and quick screens trade sensitivity for speed — a real, honest limitation worth stating plainly: a patient with serious sepsis-related organ dysfunction can still score 0 or 1, especially early on. Current sepsis guidelines do not recommend qSOFA alone as the basis for starting or withholding antibiotics; it is one input among vital signs, labs, and clinical judgment, not a gate that decides treatment by itself.
- Answer Respiratory rate ≥ 22/min — Yes or No, based on the current measured rate.
- Answer Altered mentation (GCS < 15) — Yes if the patient's mental status is below their baseline.
- Answer Systolic BP ≤ 100 mmHg — Yes or No, based on the current reading.
- Read the total, 0 to 3; a score of 2 or higher is the threshold associated with worse outcomes and warrants closer evaluation.
Worked example — three totals across the range
A patient breathing at 26 per minute (rr22 = 1) with altered mentation (1) but a systolic pressure still holding at 110 (sbp100 = 0) sums to 1 + 1 + 0 = 2 — at the threshold the Sepsis-3 consensus flags for closer evaluation of possible sepsis-related organ dysfunction.
Add a low systolic pressure of 90 to that same patient and every criterion is present: 1 + 1 + 1 = 3, the maximum score. At the other end, a patient with a respiratory rate of 16, a normal mental status, and a systolic pressure of 130 scores 0 + 0 + 0 = 0 — reassuring on this screen alone, though a low qSOFA does not by itself rule out sepsis, since the tool trades sensitivity for speed.
Questions
What does a qSOFA score of 2 or more mean?
It's the threshold the Sepsis-3 consensus definitions associate with a substantially higher risk of poor outcomes — longer ICU stays or death — among patients with suspected infection. It is meant as a prompt to evaluate further, checking full SOFA criteria and lab values, not as a stand-alone diagnosis of sepsis.
Does a low qSOFA score rule out sepsis?
No, and this is the score's most important honest limitation. qSOFA was built for speed at the cost of sensitivity, so a patient with real sepsis-related organ dysfunction can still score 0 or 1, particularly early in the illness. Current sepsis guidelines explicitly advise against using qSOFA alone to decide against antibiotics or further work-up when clinical suspicion remains.
How is qSOFA different from the full SOFA score?
Full SOFA scores six organ systems using laboratory data — creatinine, bilirubin, platelets, and more — and is designed for patients already being monitored in an ICU. qSOFA strips that down to three bedside checks that need no labs at all: respiratory rate, mentation, and blood pressure. It sacrifices some accuracy for something the full score can't offer outside intensive care — a result in under a minute.
Can qSOFA be used to decide whether to start antibiotics?
Not on its own. The Seymour et al. derivation and validation study behind qSOFA, published alongside the Sepsis-3 definitions in JAMA in 2016, positioned it as a screening prompt, and current guidelines are explicit that antibiotic decisions should rest on the fuller clinical picture — vital signs, labs, source of infection, and judgment — rather than a three-item bedside score alone.
What counts as altered mentation for this score?
Any clear change in mental status from a patient's baseline — confusion, reduced alertness, disorientation — commonly operationalized as a Glasgow Coma Scale total below 15. It doesn't require a formal GCS calculation to apply the criterion; a documented, noticeable change in how alert or oriented a patient normally is counts.
References
- Singer M et al. Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA, 2016 (PubMed)
- Seymour CW et al. Assessment of Clinical Criteria for Sepsis (Sepsis-3 derivation/validation). JAMA, 2016 (PubMed)
- CDC — About Sepsis
Read this first: This instrument computes a screening figure from population formulas — it is not a diagnosis, and it cannot see the whole picture a clinician can. Use it to inform a conversation, not to replace one.