This qSOFA calculator scores the quick Sequential Organ Failure Assessment — three bedside criteria (respiratory rate ≥ 22, systolic BP ≤ 100 mmHg, altered mentation GCS < 15) used since Sepsis-3 (2016) to flag infected patients at higher risk of poor outcomes. Two or more points is the published alert threshold. It needs no laboratory, which is both its purpose and its limitation.

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Three Observations, One Raise-the-Alarm Threshold

qSOFA was introduced with the Sepsis-3 definitions (Singer et al., JAMA 2016) as the bedside distillation of the full SOFA score: of all the organ-system variables, three clinical signs — tachypnea ≥ 22, systolic hypotension ≤ 100, and any mentation change short of a perfect GCS 15 — identified infected patients, outside the ICU, likely to have prolonged ICU stays or die in hospital. The threshold of ≥ 2 was chosen because mortality climbed steeply there (in the original analyses, qSOFA ≥ 2 in non-ICU encounters was associated with in-hospital mortality in the ≥ 10% range and risk several-fold above qSOFA 0–1). Its intended use was never diagnosis of sepsis — Sepsis-3 defines sepsis by a SOFA rise ≥ 2 from infection-driven organ dysfunction — but prompt recognition: a flag that says “assess for organ dysfunction now, draw the lactate, start the bundle clock.”

The decade since has been a fair fight about its sensitivity: qSOFA is specific but misses a real share of patients who deteriorate (sensitivity for mortality/sepsis outcomes in many ED studies lands ~50–70%), and the Surviving Sepsis Campaign's 2021 guideline explicitly recommends against qSOFA as a lone screening tool versus NEWS, MEWS or SIRS-based screens. The balanced reading, and the one this calculator prints under every result: qSOFA ≥ 2 is a meaningful alarm worth acting on; qSOFA < 2 is not an all-clear. Pair it with a full early-warning score (our NEWS2 calculator) and serial reassessment — the instruments are complements arguing for the same vigilance from different angles.

Worked Example

  • Defaults: an infected patient, mentation altered (GCS 14) but RR 18 and SBP 118 → qSOFA = 1 — under threshold, and precisely the profile that teaches the sensitivity lesson: this patient still merits full sepsis assessment on clinical grounds; qSOFA abstains, it does not acquit.
  • The classic positive: pneumonia patient, RR 26 (+1), SBP 96 (+1), alert → 2 — threshold met before any lab returns; lactate, cultures, antibiotics clock starts on three observations and a blood pressure cuff.
  • The full house: RR 30, SBP 88, GCS 13 → 3 — in validation cohorts the highest-mortality stratum; resuscitation and escalation conversations happen now, with the full SOFA and ICU referral in parallel.

qSOFA Discipline

  • Score with current, honest vitals — a respiratory rate estimated as “18” by habit rather than counted for 30–60 seconds is the commonest data error in every early-warning system.
  • Mentation means GCS < 15 — including the subtler presentations (new confusion, AVPU below Alert) that families notice first; collateral history is a vital sign here.
  • Serial scores beat single scores: a qSOFA rising 0 → 1 → 2 across an ED stay is a trajectory, and trajectories trigger escalation even before any threshold is crossed.
  • Populations where baselines shift the criteria (pregnancy, COPD with chronic tachypnea, beta-blocked patients, the very elderly) demand judgment around the numbers — the score is an adjunct printed on the chart, not the chart's author.
  • Never let a qSOFA of 0–1 delay antibiotics in a patient you believe is septic: the bundle is driven by clinical diagnosis, with scores documenting risk alongside.

Related Tools

Frequently Asked Questions

How is qSOFA calculated?

One point each for: respiratory rate ≥ 22/min, systolic blood pressure ≤ 100 mmHg, and altered mentation (Glasgow Coma Scale < 15). Score 0–3. A score ≥ 2 in a patient with suspected infection is the Sepsis-3 alert threshold associated with increased risk of in-hospital mortality and prolonged ICU care. This calculator sums the three bedside items and prints the threshold interpretation with its limitations attached.

What does qSOFA ≥ 2 mean?

In the Sepsis-3 derivation and validation cohorts, infected patients outside the ICU scoring ≥ 2 had markedly higher in-hospital mortality — commonly ~10% or more in absolute terms, several-fold the qSOFA 0–1 baseline. It signals “high risk of poor outcome from this infection; perform full organ-dysfunction assessment (SOFA/lactate) and treat per sepsis bundle now.” It is a risk flag that accelerates a workup, not a diagnosis of sepsis itself (which requires demonstrating infection-related organ dysfunction).

Does qSOFA < 2 rule out sepsis?

No — and this is the most important sentence on the page. qSOFA's sensitivity as a standalone screen is limited (many studies find it misses a third to half of patients with sepsis or deterioration), and the Surviving Sepsis Campaign 2021 explicitly recommends against using it as the sole screening instrument. Patients deteriorate below qSOFA 2 every day; NEWS2 and clinical reassessment catch more of them. Treat qSOFA as a specific alarm bell, not a clearance certificate.

qSOFA vs SOFA — what's the difference?

The full SOFA score grades six organ systems (oxygenation, platelets, bilirubin, cardiovascular support, GCS, renal function) using laboratory and treatment data — the Sepsis-3 definition itself (a rise ≥ 2 = sepsis). qSOFA is its three-item bedside proxy designed for settings and moments where labs aren't back yet: no bloods, no ABG, no urine output chart. qSOFA flags who needs the SOFA workup urgently; it was never intended to replace SOFA where SOFA can be computed.

qSOFA vs NEWS2 — which is better?

Different jobs. NEWS2 is the broader deterioration early-warning system (seven physiological variables, graded) used for all acutely ill patients, with better sensitivity for decline. qSOFA is narrower — infection-context mortality risk with three items — and more specific at its top end. Contemporary practice patterns: NEWS2 (or MEWS) for general screening and trending, qSOFA as an adjunct prompt within sepsis pathways, lactate and SOFA for confirmation and grading. Our NEWS2 calculator is the companion tool for the screening role.

Why these three criteria?

They were the strongest bedside predictors in the Sepsis-3 data task-force analyses of large encounter databases: respiratory rate captures pulmonary/metabolic compensation, systolic pressure captures cardiovascular failure without needing vasopressor data, and mentation captures CNS dysfunction. All three are measurable in a corridor, a ward or an ambulance with no laboratory — the design constraint was “usable at first contact anywhere,” and the price of that constraint is the sensitivity discussed above.

How often should qSOFA be repeated?

With every set of observations in a patient with suspected infection — it's three items and seconds to compute. Sepsis physiology evolves over hours; a single admission score is a photograph. Rising scores or failure to improve with treatment are escalation triggers in most sepsis pathways, and the trend is also the honest way to audit whether recognition-to-antibiotic times are improving in a department. Document the score and its time with each observation round.

Is this qSOFA calculator free?

Yes — free and instant, reproducing the published Sepsis-3 criteria as an educational aid; sepsis recognition and management remain the treating team's, guided by current Surviving Sepsis guidance and local protocol.