qSOFA Score Calculator (Quick SOFA)
The qSOFA (quick Sequential Organ Failure Assessment) score is a rapid, bedside screening tool for identifying patients with suspected infection who are at high risk of poor outcomes outside the ICU. Enter the three clinical criteria below. The score and risk category update instantly, with a step-by-step breakdown and clinical guidance.
Formula
Worked example
A 68-year-old presents with suspected pneumonia. GCS = 14 (confused), respiratory rate = 24 breaths/min, systolic BP = 95 mmHg. Altered mental status: 1 point. RR >= 22: 1 point. SBP <= 100: 1 point. Total = 3/3. This is a high-risk score indicating urgent evaluation for sepsis with organ dysfunction.
What is the qSOFA score?
The qSOFA (quick Sequential Organ Failure Assessment) score is a three-item clinical screening tool developed by Singer et al. and published in JAMA in 2016 as part of the Sepsis-3 consensus definitions. It is designed to rapidly identify patients with suspected infection who are at high risk of poor outcomes - particularly prolonged ICU stays and in-hospital death - without requiring any laboratory tests. The three criteria are: altered mental status (a Glasgow Coma Scale score below 15), an elevated respiratory rate (22 breaths per minute or more), and a low systolic blood pressure (100 mmHg or less). Each criterion that is present earns one point, for a maximum total of three. A score of 2 or 3 is considered a positive result and signals that the patient warrants urgent, thorough evaluation. The tool is intended for use outside the ICU, such as in emergency departments, hospital wards, and pre-hospital settings, where the full SOFA score requiring laboratory values may not be immediately accessible.
How to use this calculator
Select whether the patient has an altered mental status (any GCS below 15, including new confusion, drowsiness, or reduced responsiveness). Enter the respiratory rate in breaths per minute and the systolic blood pressure in mmHg. The qSOFA score and risk category update instantly. A score of 0 or 1 indicates that the patient does not meet the high-risk threshold, though a negative qSOFA does not rule out sepsis given the tool's limited sensitivity of roughly 46%. A score of 2 or 3 should prompt urgent clinical action: measuring serum lactate, obtaining blood cultures before antibiotics, calculating the full SOFA score to assess organ dysfunction, and consulting ICU or infectious disease services as appropriate. This calculator is for use in adult patients (18 years and older) with suspected infection. It is not validated for use in ICU patients, for whom the full SOFA score is recommended, and it is not a diagnostic tool for sepsis.
qSOFA vs. SOFA vs. SIRS: key differences
Three scoring systems are commonly used in suspected sepsis: SIRS (systemic inflammatory response syndrome criteria), qSOFA, and the full SOFA score. SIRS (temperature, heart rate, respiratory rate, and WBC count) was used under previous Sepsis-1 and Sepsis-2 definitions and is highly sensitive but poorly specific - most hospitalized patients meet SIRS criteria at some point. The full SOFA score (including PaO2/FiO2 ratio, platelet count, bilirubin, creatinine, and vasopressor use) is the gold standard for defining sepsis and quantifying organ dysfunction under the Sepsis-3 definition, but it requires laboratory values and is more complex. qSOFA sits between these: faster than SOFA because it needs no labs, and more specific than SIRS for identifying patients at risk of poor outcomes. The 2021 Surviving Sepsis Campaign guidelines note that qSOFA should not be used as the sole screening tool because of its low sensitivity, and recommend combining it with clinical judgment, lactate, and other early warning scores such as NEWS (National Early Warning Score) for the best performance.
Clinical evidence and limitations
qSOFA was validated in a large retrospective cohort of more than 1.3 million patient encounters across two health systems. In patients outside the ICU, a qSOFA score of 2 or more had better discrimination for in-hospital mortality than SIRS criteria (AUROC 0.81 vs. 0.76). However, subsequent prospective studies have identified important limitations. Sensitivity is approximately 46 to 60%, meaning that roughly half of patients who ultimately die of sepsis-related causes will have an initial qSOFA score below 2. It performs less well in emergency departments than in ward settings, and less well in low-income settings where baseline vital signs may differ. The score does not account for fever, leukocytosis, or elevated lactate, all of which can be early markers of infection-related organ stress. For these reasons, the 2021 Surviving Sepsis Campaign explicitly advises that qSOFA should be used alongside - not instead of - clinical judgment, SIRS, NEWS, and laboratory evaluation. qSOFA is best used as an aid to clinical decision-making, not a replacement for it.
qSOFA Score Interpretation
| Score | Risk Category | In-Hospital Mortality Risk | Recommended Action |
|---|---|---|---|
| 0 | Low Risk | Baseline (low) | Standard monitoring; reassess if condition changes |
| 1 | Indeterminate | Slightly elevated | Increased monitoring; consider SIRS or NEWS; clinical judgment required |
| 2 | High Risk | 3- to 14-fold increase | Urgent evaluation: lactate, blood cultures, full SOFA, consider ICU |
| 3 | High Risk | 3- to 14-fold increase | Urgent evaluation: lactate, blood cultures, full SOFA, ICU assessment |
Risk stratification for patients with suspected infection outside the ICU. Based on Singer et al., JAMA 2016 (Sepsis-3).
Frequently asked questions
What is a positive qSOFA score?
A qSOFA score of 2 or 3 out of a possible 3 is considered positive. A positive result indicates that the patient is at high risk for poor outcomes, including prolonged ICU stays and in-hospital death, and warrants urgent evaluation for sepsis with organ dysfunction. A score of 0 or 1 is below the positive threshold, though it does not rule out sepsis.
Does qSOFA diagnose sepsis?
No. qSOFA is a risk-stratification and screening tool, not a diagnostic test. Sepsis is defined under the Sepsis-3 guidelines as life-threatening organ dysfunction caused by a dysregulated host response to infection, operationalized as a suspected infection plus an acute SOFA score increase of 2 or more points. A positive qSOFA should trigger a full clinical assessment and SOFA score calculation, not automatically confirm a sepsis diagnosis.
Can I use qSOFA in the ICU?
qSOFA was designed for patients outside the ICU, such as those in the emergency department or general hospital wards. For ICU patients, the full SOFA score is recommended because it more comprehensively captures organ dysfunction and has been validated in that setting. The original Sepsis-3 paper found that qSOFA discriminated poorly for ICU patients compared to outside the ICU.
What counts as altered mental status for qSOFA?
Any new change in mental status that results in a Glasgow Coma Scale (GCS) score below 15 meets the criterion. This includes new confusion, drowsiness, agitation, lethargy, or any reduction in the level of consciousness. The change must be new or acute - a patient with a known chronic cognitive impairment at their baseline GCS would not necessarily meet the criterion unless there is an acute deterioration from their normal.
Why does qSOFA not include fever or white blood cell count?
The qSOFA was specifically designed to be a rapid, bedside tool requiring no laboratory tests and no thermometer reading. Its three criteria - altered mental status, respiratory rate, and systolic blood pressure - are all immediately observable. Fever and WBC count are captured by the SIRS criteria, which require slightly more equipment and lab access. The Sepsis-3 authors found that the qSOFA criteria were more specifically associated with organ dysfunction risk than SIRS criteria alone.
Should I start antibiotics immediately if qSOFA is positive?
A positive qSOFA score (2 or 3) should prompt urgent evaluation, not automatic antibiotic administration. The recommended steps include assessing the patient fully, obtaining blood cultures before antibiotics if clinically feasible, measuring serum lactate, and calculating the full SOFA score to determine if organ dysfunction is present. The 2021 Surviving Sepsis Campaign guidelines recommend starting broad-spectrum antibiotics within 1 hour for septic shock, and within 3 hours for probable sepsis. Clinical judgment must guide the exact timing and selection.