qSOFA Score Calculator (Quick SOFA) for Sepsis Screening
Free qSOFA calculator for bedside sepsis screening. 3 criteria — respiratory rate, blood pressure, mental status — with instant interpretation, SIRS comparison, and Hour-1 Bundle guidance.
qSOFA Criteria Assessment
3 bedside criteria — no labs required. Score ≥2 is positive.
SSC 2021: Not Recommended as Sole Screen
The Surviving Sepsis Campaign recommends against using qSOFA as a single screening tool due to ~46% sensitivity. A negative qSOFA does NOT rule out sepsis.
Note: qSOFA threshold is ≥22, higher than SIRS threshold of >20.
Any alteration from baseline. Even GCS 14 = 1 point. Consider baseline in dementia or intoxication.
Note: qSOFA threshold is ≤100, not <90 as in some shock definitions.
Mnemonic: HAT
Threshold Differences
qSOFA Score
Enter values to calculate
About This Calculator
What is the qSOFA Score?
The qSOFA (Quick Sequential Organ Failure Assessment) score is a 3-item bedside tool introduced in 2016 as part of the Sepsis-3 consensus definitions. It uses respiratory rate (≥22), systolic blood pressure (≤100 mmHg), and altered mental status (GCS <15) to identify patients with suspected infection who are at risk for poor outcomes outside the ICU.
How does qSOFA work?
The qSOFA assigns 1 point for each criterion met: respiratory rate ≥22 breaths/min, systolic blood pressure ≤100 mmHg, and altered mental status (any GCS <15). A score of ≥2 is considered positive and should prompt further evaluation for organ dysfunction using the full SOFA score. The total score ranges from 0 to 3.
Important Controversy
The 2021 Surviving Sepsis Campaign issued a strong recommendation AGAINST using qSOFA as a sole screening tool for sepsis, citing its low sensitivity (~46%). qSOFA was designed as a prognostic tool to identify patients at highest risk, not as a diagnostic screening tool. A negative qSOFA does NOT rule out sepsis — over 55% of truly septic patients may have qSOFA <2 initially.
Clinical Applications
- Bedside risk stratification for patients with suspected infection outside the ICU
- Prompts further evaluation with full SOFA score when positive (≥2)
- Identifies the sickest patients who account for a disproportionate share of poor outcomes
- Should be used alongside clinical judgment, not as a replacement
- The HAT mnemonic helps remember criteria: Hypotension, Altered mentation, Tachypnea
Formula
qSOFA = (RR ≥ 22) + (SBP ≤ 100) + (GCS < 15); Range 0–3, Positive ≥ 2Each criterion met = 1 point. Score ≥2 is positive and should prompt further evaluation for organ dysfunction (full SOFA score). qSOFA is a screening/prognostic tool, not a diagnostic tool for sepsis.
Clinical Considerations
- •SSC 2021 recommends AGAINST using qSOFA as a sole screening tool due to ~46% sensitivity.
- •A negative qSOFA does NOT rule out sepsis — over 55% of septic patients may have qSOFA <2.
- •qSOFA is a prognostic tool (identifies high-risk patients), not a diagnostic tool for sepsis.
- •If clinical suspicion for sepsis exists, pursue evaluation regardless of qSOFA score.
- •qSOFA does not include fever, heart rate, or WBC — traditionally important sepsis markers.
Limitations
- •Sensitivity only ~43–48% — misses more than half of patients who will have poor outcomes.
- •Not designed as a screening tool — derived for prognosis, not diagnosis.
- •Performs poorly in the ICU (AUROC 0.66) where most patients already meet criteria.
- •GCS assessment is subjective — baseline cognitive impairment, intoxication, and sedation confound scoring.
- •No account for baseline vitals — chronic hypotension or chronic tachypnea (e.g., COPD) may cause false positives.
- •No lactate component — misses cryptic sepsis (normal vitals + elevated lactate).
- •Not validated in pediatrics — Phoenix Sepsis Score is the pediatric equivalent.
Interpretation Guide
| Range | Classification | Recommendation |
|---|---|---|
| <-0 | Low Risk | Low risk. Continue standard care. IMPORTANT: qSOFA 0 does NOT rule out sepsis — 55% of septic patients may have qSOFA <2. Maintain clinical vigilance and re-assess if clinical concern persists. |
| 1-1 | Low-Intermediate Risk | Low-intermediate risk. Monitor closely for clinical deterioration. Consider early re-assessment. If clinical suspicion for sepsis remains, pursue full SOFA evaluation regardless of score. |
| 2-2 | High Risk — qSOFA Positive | qSOFA POSITIVE. Assess for organ dysfunction with full SOFA score. Consider ICU admission. Initiate Hour-1 Sepsis Bundle: lactate, blood cultures, broad-spectrum antibiotics, IV crystalloid 30 mL/kg if hypotensive or lactate ≥4. |
| 3-3 | Very High Risk — qSOFA Positive | qSOFA POSITIVE — all criteria met. Urgent sepsis evaluation and aggressive management. Full SOFA score, ICU admission, Hour-1 Bundle immediately. Consider vasopressors if MAP <65 despite fluid resuscitation. |
Frequently Asked Questions
What is the qSOFA score?
The qSOFA (Quick Sequential Organ Failure Assessment) score is a 3-item bedside tool that identifies patients with suspected infection who are at risk for poor outcomes. It uses respiratory rate (≥22), systolic blood pressure (≤100 mmHg), and altered mental status (GCS <15). A score of ≥2 is positive. It was introduced as part of the Sepsis-3 definitions in 2016.
What does a positive qSOFA score mean?
A positive qSOFA (score ≥2) indicates that a patient with suspected infection has a 3- to 14-fold increased risk of in-hospital mortality compared to qSOFA <2. It should prompt further evaluation for organ dysfunction using the full SOFA score, not an automatic sepsis diagnosis. In-hospital mortality with qSOFA ≥2 is approximately 15–40%.
Is qSOFA recommended for sepsis screening?
The 2021 Surviving Sepsis Campaign (SSC) issued a strong recommendation AGAINST using qSOFA as a sole screening tool for sepsis due to its low sensitivity (~46%). This means qSOFA misses more than half of septic patients. The SSC recommends using validated screening tools with higher sensitivity or clinical judgment instead.
What is the difference between qSOFA and SIRS?
SIRS (Systemic Inflammatory Response Syndrome) uses 4 criteria (temperature, heart rate, respiratory rate >20, WBC) with high sensitivity (~85%) but low specificity (~41%). qSOFA uses 3 criteria (RR ≥22, SBP ≤100, altered mentation) with low sensitivity (~46%) but high specificity (~89%). SIRS catches more sepsis cases but with more false alarms; qSOFA identifies the sickest patients but misses many.
What is the difference between qSOFA and SOFA?
qSOFA is a 3-item bedside screening tool (no labs needed) used outside the ICU to identify at-risk patients. SOFA (Sequential Organ Failure Assessment) is a 6-organ-system scoring tool that requires laboratory values and is used to define and diagnose sepsis per Sepsis-3 criteria (suspected infection + SOFA increase ≥2). qSOFA prompts SOFA evaluation.
What are the 3 qSOFA criteria?
The 3 qSOFA criteria are: (1) Respiratory rate ≥ 22 breaths/min, (2) Altered mental status (any GCS < 15), and (3) Systolic blood pressure ≤ 100 mmHg. The HAT mnemonic helps: Hypotension, Altered mentation, Tachypnea. Each criterion met = 1 point, total score 0–3.
Can qSOFA rule out sepsis?
No. A negative qSOFA (score 0 or 1) does NOT rule out sepsis. The qSOFA has a sensitivity of only ~43–48%, meaning it misses more than half of patients who will have poor outcomes from sepsis. If clinical suspicion exists, pursue further evaluation (full SOFA, lactate, blood cultures) regardless of the qSOFA score.
What is the Hour-1 Sepsis Bundle?
The Hour-1 Sepsis Bundle (SSC 2018) includes: (1) Measure lactate level, (2) Obtain blood cultures before antibiotics, (3) Administer broad-spectrum antibiotics, (4) Begin 30 mL/kg IV crystalloid for hypotension or lactate ≥4 mmol/L, (5) Apply vasopressors if MAP <65 mmHg despite fluid resuscitation. Every hour of delayed antibiotics increases mortality by approximately 4–8%.
Does qSOFA work in the ICU?
qSOFA performs poorly in the ICU (AUROC 0.66 vs 0.81 in non-ICU settings) because most ICU patients already meet qSOFA criteria. The full SOFA score (AUROC 0.74) is better for ICU patients. qSOFA was designed and validated primarily for non-ICU settings — ward patients and ED patients.
How accurate is qSOFA compared to clinical judgment?
A 2024 study in Annals of Emergency Medicine (2,484 encounters) found that physician clinical gestalt dramatically outperforms all scoring systems: physician gestalt AUC 0.90 vs qSOFA AUC 0.67. This underscores that qSOFA should support clinical judgment, not replace it.
Why was the respiratory rate threshold set at 22?
The qSOFA respiratory rate threshold of ≥22 breaths/min was derived from the data as the optimal cutoff for predicting poor outcomes. This is higher than the SIRS threshold of >20 breaths/min. The difference is important when comparing the two systems.
What mortality rates are associated with each qSOFA score?
Approximate in-hospital mortality by qSOFA score: 0 = 1–3%, 1 = 4–7%, 2 = 15–18%, 3 = 25–40%+. Patients with qSOFA ≥2 account for only 24% of infected patients but 70% of poor outcomes.
References
1. Singer M, Deutschman CS, Seymour CW, et al.. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016. doi: 10.1001/jama.2016.0287
View Source →2. Seymour CW, Liu VX, Iwashyna TJ, et al.. Assessment of Clinical Criteria for Sepsis. JAMA. 2016. doi: 10.1001/jama.2016.0288
View Source →3. Evans L, Rhodes A, Alhazzani W, et al.. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2021. Intensive Care Medicine. 2021
View Source →4. Freund Y, Lemachatti N, Krastinova E, et al.. Prognostic Accuracy of Sepsis-3 Criteria for In-Hospital Mortality Among Patients With Suspected Infection Presenting to the Emergency Department. JAMA. 2017. doi: 10.1001/jama.2016.20329
View Source →5. Levy MM, Evans LE, Rhodes A. The Surviving Sepsis Campaign Bundle: 2018 Update. Critical Care Medicine. 2018
View Source →Last updated: 2026-02-24
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