maratoolqSOFA vs SOFA
A side-by-side comparison of qSOFA Score and SOFA Score.
qSOFA (quick SOFA) and SOFA (Sequential Organ Failure Assessment) are both part of the Sepsis-3 framework but answer different questions. qSOFA is a bedside screening tool for non-ICU settings — three quick variables (mental status, respiratory rate, systolic blood pressure) that flag patients at higher risk of in-hospital death from suspected infection. SOFA is a comprehensive organ dysfunction score (six organ systems) used in the ICU to quantify severity and meet Sepsis-3 diagnostic criteria.
When to use qSOFA Score
Use qSOFA in the emergency department, ward, or pre-hospital setting for any patient with suspected infection. A score ≥ 2 of the 3 criteria flags higher mortality risk and triggers escalation (sepsis workup, ICU evaluation, antibiotic timing review). qSOFA is fast — no labs required.
When to use SOFA Score
Use SOFA in the ICU or for patients with available lab data. Sepsis-3 defines sepsis as suspected infection plus an acute increase of ≥ 2 SOFA points from baseline. SOFA quantifies dysfunction across respiration, coagulation, liver, cardiovascular, CNS, and renal systems.
Side-by-side comparison
| qSOFA | SOFA | |
|---|---|---|
| Purpose | Bedside screen for sepsis risk | Quantify organ dysfunction (Sepsis-3 criterion) |
| Setting | ED, ward, pre-hospital | ICU |
| Number of inputs | 3 (RR, SBP, mental status) | 6 organ systems (24 sub-variables) |
| Requires labs? | No | Yes (PaO2, platelets, bilirubin, creatinine) |
| Score range | 0–3 | 0–24 |
| Threshold of concern | ≥ 2 → flag for evaluation | ≥ 2 acute increase = sepsis (if infection) |
| Speed | Seconds | Minutes (labs required) |
| Sensitivity for sepsis | Lower (~60%) | Higher (when labs available) |
Bottom line
qSOFA screens outside the ICU; full SOFA diagnoses and quantifies inside it. They are complementary stages of the same Sepsis-3 algorithm.
Frequently asked questions
Should I use SIRS instead of qSOFA?
The 2016 Sepsis-3 task force replaced SIRS with qSOFA for bedside screening because SIRS is too sensitive (many non-infected patients meet criteria) and not specific to organ dysfunction. SIRS remains in some institutional protocols but qSOFA is the current standard.
What if qSOFA is negative but I still suspect sepsis?
Clinical judgment outranks any score. qSOFA has ~60% sensitivity — a negative score does not rule out sepsis. If the patient looks sick, proceed with workup and treatment regardless.
How fast does SOFA need to change to count?
Sepsis-3 defines an "acute" increase as occurring during the current illness. In a previously healthy patient, baseline SOFA is assumed = 0, so any acute SOFA ≥ 2 meets criteria.
Does qSOFA include lactate?
No — lactate is not part of qSOFA. Some institutional sepsis bundles add lactate as a screening adjunct, but it is not in the published qSOFA score.