What does qSOFA ≥2 mean?

A qSOFA score of 2 or 3 in a patient with suspected infection identifies those at higher risk of death or prolonged ICU stay. It should prompt immediate sepsis workup: blood cultures, lactate, IV antibiotics within 1 hour, fluid resuscitation if hypotensive, and assessment for organ dysfunction using the full [SOFA Score](/tools/sofa-score).

Can qSOFA be 0 but sepsis still be present?

Yes. qSOFA has approximately 75% sensitivity for sepsis. Patients can have early sepsis or septic shock with qSOFA 0–1, so persistent clinical concern should trigger full evaluation including SOFA calculation, lactate, and blood cultures. A negative qSOFA does NOT rule out sepsis.

How does qSOFA differ from SIRS criteria?

qSOFA uses 3 clinical variables requiring no labs (altered mentation, RR ≥22, SBP ≤100); SIRS uses 4 criteria including temperature and WBC. qSOFA is more specific for poor outcomes; SIRS is more sensitive for detecting any infection. Sepsis-3 (2016) formally replaced SIRS with SOFA ≥2 for the sepsis definition, though SIRS is still used in some regulatory frameworks.

Should qSOFA replace the full SOFA score?

No. qSOFA is a screening tool for use outside the ICU. The full [SOFA Score](/tools/sofa-score) remains the standard for diagnosing sepsis (suspected infection + SOFA increase ≥2) and quantifying organ dysfunction. qSOFA identifies patients who need SOFA calculation and closer monitoring — it is not a substitute for SOFA in the ICU.

What is the Sepsis-3 definition?

Sepsis-3 (Singer et al., JAMA 2016) defines sepsis as suspected infection + acute increase in SOFA score ≥2 points (presumed baseline SOFA = 0 in patients without known organ dysfunction). qSOFA ≥2 is a bedside screening tool that identifies patients likely to meet SOFA ≥2 criteria, but the formal diagnosis requires SOFA calculation.

What is the qSOFA sensitivity for sepsis?

qSOFA has approximately 69–77% sensitivity and 83–88% specificity for sepsis (from derivation and validation studies). It misses ~25% of sepsis cases. Use qSOFA as a rule-IN tool for high-risk patients, not as a rule-OUT tool. Any patient with suspected infection and clinical concern deserves workup regardless of qSOFA score.

What is septic shock according to Sepsis-3?

Septic shock = sepsis + (1) vasopressors needed to maintain MAP ≥65 mmHg AND (2) lactate >2 mmol/L, despite adequate fluid resuscitation. Hospital mortality for septic shock is approximately 40–50%. Both criteria must be met — vasopressors alone or lactate elevation alone does not meet the formal Sepsis-3 septic shock definition.

What are the most common sources of sepsis?

The most common sepsis sources are: pneumonia (~35%), urinary tract infection (~25%), abdominal infection (~20%), skin/soft tissue (~10%), bacteremia/line infection (~5%), and other/unknown (~5%). When qSOFA ≥2, identify the suspected source to guide antibiotic selection. Common empiric coverage: pneumonia (piperacillin-tazobactam ± azithromycin), UTI (ceftriaxone or pip-tazo for complicated/ICU), intra-abdominal (pip-tazo or meropenem).

Can qSOFA be used in pediatric patients?

No. qSOFA was derived and validated in adult patients. Pediatric patients have different normal vital sign ranges (higher HR and RR) that make adult qSOFA thresholds inappropriate. For pediatric sepsis screening, use the Pediatric Systemic Inflammatory Response Syndrome (PSIRS) criteria or the Phoenix Sepsis Score (2024).

How does qSOFA perform outside the hospital?

qSOFA performs well in the pre-hospital setting for identifying sepsis patients who need transport to higher-acuity care. A pre-hospital qSOFA ≥2 with suspected infection predicts ICU admission and in-hospital death with similar performance to ED settings. Paramedics can apply qSOFA without labs, making it practical for EMS triage and sepsis pre-alerts.

Online Medical Tools — qSOFA Score

Printed on 8/14/2026

For informational purposes only. This is not medical advice.

Emergency

qSOFA Score

The quick SOFA (qSOFA) is a bedside clinical tool introduced with the Sepsis-3 definitions in 2016. It uses three simple criteria — altered mentation, respiratory rate ≥ 22, and systolic blood pressure ≤ 100 mmHg — each scored 0 or 1. A qSOFA score ≥ 2 identifies patients with suspected infection who are at greater risk of prolonged ICU stay or death. Unlike the full SOFA score, qSOFA requires no laboratory tests and can be rapidly assessed at the bedside, in the ED, or on the ward. For confirmed sepsis, complete SOFA Score and APACHE II for full severity assessment. Assess hemodynamic status with MAP Calculator (target MAP ≥65) and Shock Index. Monitor altered mentation with Glasgow Coma Scale. Screen for pneumonia with CURB-65. Track renal impairment with eGFR Calculator.

Formula: qSOFA = sum of 3 criteria (each 0 or 1). Range 0-3. Positive ≥ 2.

Systolic BP ≤ 100 mmHg

Respiratory rate ≥ 22 breaths/min

Altered mentation (GCS < 15)

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How It Works

Assess 3 variables at bedside without labs

Assess three bedside variables that require no laboratory tests: (1) Altered mentation — new onset confusion or GCS <15 (score 1 if present); (2) Respiratory rate ≥22 breaths/min (score 1 if present); (3) Systolic BP ≤100 mmHg (score 1 if present). Each criterion is binary (0 or 1). The entire assessment takes under 60 seconds with a blood pressure cuff and brief mental status check.

Sum the criteria (0–3)

Sum the three binary criteria. Score 0–3. A score ≥2 with suspected infection identifies patients at high risk for prolonged ICU stay or death and warrants immediate sepsis workup and treatment. Score 0–1 does not exclude sepsis — qSOFA is a screen for HIGH risk, not a rule-out tool.

Act on a positive result without delay

qSOFA ≥2 with suspected infection: immediately draw blood cultures (2 sets before antibiotics), obtain serum lactate, establish IV access, start broad-spectrum antibiotics within 1 hour of recognition, initiate 30 mL/kg IV crystalloid if SBP ≤100 or lactate ≥4 mmol/L, calculate full [SOFA Score](/tools/sofa-score) for organ dysfunction assessment, and consider ICU consultation. Septic shock = sepsis + vasopressors needed to maintain MAP ≥65 mmHg + lactate ≥2 mmol/L despite fluids.

Who Uses the qSOFA Score

Rapid Bedside Sepsis Screening in Emergency Department

Emergency physicians, triage nurses

Apply qSOFA in the first minutes of evaluation when infection is suspected — before lab results are available. qSOFA ≥2 identifies patients at 2–5× higher risk of in-hospital death. Early identification triggers the sepsis bundle, including blood cultures before antibiotics. For confirmed sepsis, calculate full [SOFA Score](/tools/sofa-score) for organ dysfunction staging and [APACHE II](/tools/apache-ii) for severity documentation.

Hospital Ward Sepsis Identification

Ward nurses, hospitalists, general medicine teams

qSOFA can be applied at any vital signs assessment on the ward. A patient who deteriorates overnight with qSOFA ≥2 warrants urgent medical review and sepsis workup. Pair with [NEWS2 Score](/tools/news2-score) for comprehensive early warning. qSOFA on the ward has better performance than in the ICU (where all patients are already monitored intensively).

Pre-Hospital EMS Triage for Sepsis

Paramedics, emergency medical technicians

Pre-hospital qSOFA assessment guides transport decision (community hospital vs tertiary center) and pre-arrival sepsis alerts. Paramedics can assess RR, BP, and mentation without equipment beyond a BP cuff. A field qSOFA ≥2 with suspected infection should trigger pre-hospital IV access, fluid administration per protocol, and pre-alert for the sepsis team.

Starting Sepsis Bundle Initiation

All clinical staff, sepsis champions

qSOFA ≥2 with suspected infection triggers the CMS SEP-1 Hour-1 Bundle: (1) measure lactate, (2) obtain blood cultures before antibiotics, (3) administer broad-spectrum antibiotics, (4) 30 mL/kg IV crystalloid for hypotension or lactate ≥4, (5) vasopressors for persistent hypotension. Document qSOFA score in the chart as evidence of sepsis recognition time.

Research Sepsis Identification and Cohort Definition

Clinical researchers, epidemiologists

qSOFA is widely used in sepsis research for cohort identification and as an inclusion criterion in clinical trials. As part of the Sepsis-3 framework, qSOFA provides a reproducible, standardized bedside screening tool that can be applied retrospectively in EHR data. Compare with SIRS criteria and SOFA score when designing study populations.

Outpatient and Nursing Home Infection Severity Assessment

Primary care physicians, nursing home staff

In outpatient or nursing home settings where lab access is limited, qSOFA provides an immediate severity assessment for patients with suspected infection. qSOFA ≥2 in a nursing home resident with suspected UTI, pneumonia, or cellulitis warrants transfer to the ED rather than outpatient antibiotic management. Even qSOFA 1 with high clinical concern warrants urgent evaluation.

Pro Tips

qSOFA ≥2 is NOT the same as Sepsis-3 — SOFA ≥2 is the formal definition

qSOFA was proposed as a bedside SCREEN, not the formal definition. Sepsis-3 defines sepsis as suspected infection + acute SOFA increase ≥2 points. qSOFA ≥2 identifies patients who likely have sepsis and need SOFA calculation and further workup. Do not diagnose sepsis based on qSOFA alone — always calculate SOFA to confirm organ dysfunction.

Altered mentation is the most predictive single qSOFA item for mortality

Of the three qSOFA criteria, new-onset altered mentation carries the strongest independent mortality signal. A confused patient with normal RR and BP (qSOFA = 1) still warrants sepsis consideration. When only one criterion is positive, altered mentation should increase your clinical urgency more than RR or BP criterion alone.

qSOFA has lower sensitivity (~75%) than SIRS but better specificity for outcome

qSOFA misses approximately 25% of patients who will be diagnosed with sepsis (lower sensitivity than SIRS). However, qSOFA-positive patients are more likely to have a serious outcome (higher specificity). Use qSOFA as a rule-IN tool for high-risk patients who need immediate action, not as a rule-OUT tool for lower-risk patients.

Do NOT wait for culture results before starting antibiotics

Blood cultures should be drawn before antibiotics but antibiotics should NOT be delayed waiting for culture results. The Surviving Sepsis Campaign 1-Hour Bundle (Levy et al., Crit Care Med 2018) recommends antibiotics within 1 hour of sepsis recognition. Every hour of antibiotic delay in septic shock increases mortality by 7–10%. If unable to draw cultures within 45 minutes, start antibiotics anyway.

Lactate ≥4 mmol/L = septic shock even with normal BP

A patient with qSOFA ≥2 and lactate ≥4 mmol/L meets criteria for septic shock by tissue hypoperfusion, even if systolic BP is currently normal. Lactate is a more sensitive indicator of shock than BP in patients compensating with tachycardia and peripheral vasoconstriction. Obtain lactate immediately when qSOFA ≥2.

qSOFA is NOT validated for ICU patients — use SOFA in the ICU

qSOFA was derived and validated in non-ICU settings. In the ICU, SOFA is the appropriate tool for organ dysfunction quantification and sepsis diagnosis. ICU patients may have qSOFA criteria met for non-infectious reasons (post-op state, sedation, chronic illness) making qSOFA less informative. Use daily SOFA scores for ICU patients.

Septic shock requires both vasopressors AND lactate ≥2 mmol/L

Septic shock = sepsis + (1) vasopressors needed to maintain MAP ≥65 mmHg despite adequate fluid resuscitation AND (2) serum lactate >2 mmol/L. Both criteria must be met. A patient requiring vasopressors with lactate <2 mmol/L does not meet the formal Sepsis-3 septic shock definition, though the clinical urgency remains high.

SIRS criteria are still used by CMS for SEP-1 quality reporting

Despite Sepsis-3 replacing SIRS in the formal clinical definition, CMS's SEP-1 quality measure still uses SIRS criteria + infection as the bundle trigger for regulatory purposes. Hospitals must track SIRS-based sepsis identification for CMS reporting alongside qSOFA/SOFA-based clinical practice. Check your institution's protocol for which framework governs bundle timing documentation.

Document exact time of qSOFA recognition — this is the 'sepsis clock'

The sepsis bundle 1-hour clock starts at sepsis recognition. Document in the chart: 'qSOFA ≥2 recognized at [time]. Suspected source: [UTI/pneumonia/other]. Sepsis bundle initiated at [time].' This documentation is essential for CMS SEP-1 compliance, medicolegal protection, and quality improvement tracking. Missing this documentation is a major hospital liability risk.

Common Questions About Your Results

Yes. qSOFA ≥2 with suspected infection defines the threshold for sepsis concern, regardless of the suspected source. A urinary tract infection can cause sepsis and even septic shock, particularly in elderly or immunocompromised patients. If qSOFA ≥2, implement the 1-Hour Bundle: blood cultures, lactate, antibiotics, IV access. You can always de-escalate if the patient responds quickly and lactate is <2, but you cannot undo the harm from delayed treatment in true sepsis.

Clinical concern always overrides a negative screen. qSOFA 1 does not rule out sepsis — it only fails to identify the patient as HIGH risk by this specific tool. If you have clinical concern based on: appearance (toxic, diaphoretic, mottled), vital sign trends, lactate ≥2, or source of infection with systemic signs, initiate workup and treatment regardless of qSOFA score. Obtain blood cultures, lactate, and CBC/CMP. Start antibiotics if sepsis is clinically suspected even with qSOFA 1.

No. SIRS criteria (≥2 of: temp abnormal, HR >90, RR >20 or pCO2 <32, WBC abnormal) require temperature and white blood cell count, and were historically used as the sepsis definition. qSOFA uses 3 different clinical variables (altered mentation, RR ≥22, SBP ≤100) that require no labs. qSOFA has higher specificity for predicting poor outcomes; SIRS has higher sensitivity for detecting any infection. Some institutions still use SIRS for CMS SEP-1 reporting while using qSOFA/SOFA clinically.

The altered mentation criterion in qSOFA refers to ACUTE or WORSENING mentation change from the patient's baseline, not chronic cognitive impairment. A demented patient who is at their cognitive baseline should score 0. The same patient with acutely worsened confusion beyond their typical dementia (e.g., no longer recognizing family) should score 1. Document the patient's cognitive baseline clearly in the chart to allow accurate serial assessments.

Evidence-Based Methodology

qSOFA and Sepsis-3 definition published by Seymour et al. and Singer et al. (JAMA 2016). qSOFA was derived from analysis of 1.3 million patient records in two academic EHR databases. SOFA ≥2 defines sepsis; qSOFA ≥2 was proposed as a bedside screener. Subsequent validation: qSOFA sensitivity 69–77% for sepsis, specificity 83–88%. The ACEP and SCCM/ESICM endorse qSOFA as a rapid clinical tool while maintaining SOFA as the formal definition standard. The Surviving Sepsis Campaign 1-Hour Bundle (Levy et al., Crit Care Med 2018) focuses on early antibiotics, cultures, lactate, and fluids.

Clinical Content Trust

Last reviewed:: April 21, 2026
Guideline version:: General evidence framework v2026.04
Source set version:: Primary-source set v1

How to Interpret Your Result

Your qSOFA score ranges from 0 to 3 based on three bedside criteria: systolic blood pressure 100 mmHg or below, respiratory rate 22 or above, and altered mentation (GCS below 15). A score of 0 or 1 suggests lower risk of poor outcomes from infection, though it does not rule out sepsis. Standard monitoring and clinical reassessment should continue.

A qSOFA score of 2 or 3 identifies patients with suspected infection who are at significantly higher risk of prolonged ICU stay or in-hospital death. This should prompt immediate action: obtain blood cultures and lactate, administer broad-spectrum antibiotics within one hour, initiate fluid resuscitation if hypotensive, and assess for organ dysfunction using the full SOFA score. Early recognition and treatment of sepsis are strongly associated with improved survival.

It is important to understand that qSOFA is a risk stratification tool, not a diagnostic test for sepsis. A positive qSOFA (score of 2 or more) identifies patients who need urgent attention, but the definitive diagnosis of sepsis under Sepsis-3 criteria requires evidence of organ dysfunction as measured by a SOFA score increase of 2 or more points in the setting of suspected infection.

When to Use This Tool

The qSOFA should be used as a rapid bedside screening tool for patients with suspected or confirmed infection who are outside the ICU — particularly on general medical and surgical wards, in the emergency department, and in urgent care settings. It is designed to quickly identify patients who may be developing sepsis and who need escalation of care, without waiting for laboratory results.

qSOFA is particularly useful in resource-limited settings or time-critical situations where laboratory values are not immediately available. It can be assessed in under one minute using only a blood pressure cuff, observation of respiratory rate, and a brief mental status assessment. It should be used as a trigger for further evaluation, not as a replacement for clinical judgment or comprehensive sepsis assessment.

Limitations

The qSOFA has higher specificity but lower sensitivity compared to the older SIRS criteria for identifying sepsis. This means that while a positive qSOFA reliably identifies high-risk patients, a negative qSOFA (score of 0 or 1) does not rule out sepsis. Some patients with serious infections and organ dysfunction will have a qSOFA of 0 or 1 and may be missed if qSOFA is used as the sole screening tool.

qSOFA was derived and validated primarily in adult patients and should not be applied to pediatric populations without modification. It was also designed for use outside the ICU — in ICU patients, the full SOFA score is more appropriate because these patients are already receiving intensive monitoring and may have qSOFA abnormalities from non-infectious causes.

The three qSOFA criteria can be abnormal for many reasons other than sepsis, including pain, anxiety, neurological conditions, respiratory disease, and medication effects. A positive qSOFA in a patient with a known alternative explanation for these findings should still prompt consideration of infection, but clinical context is essential. Some professional societies have expressed concern that qSOFA may delay recognition of sepsis compared to SIRS-based screening, and institutional protocols should be followed.

Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.

Changelog

April 21, 2026 · trust-baseline
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