Last verified · v1.0

Calculator · health

Q Sofa Score Calculator (Quick Sequential Organ Failure Assessment)

Quickly calculate qSOFA score using respiratory rate, altered mental status, and systolic BP to screen for sepsis risk.

FreeInstantNo signupOpen source

Inputs

Respiratory Rate

Altered Mental Status (GCS < 15)

Systolic Blood Pressure

qSOFA Score

—

Get a plain-English breakdown of your result with practical next steps.

qSOFA Score—points

The formula

How the
result is
computed.

What Is the qSOFA Score?

The quick Sequential Organ Failure Assessment (qSOFA) score is a rapid bedside screening tool introduced as part of the landmark 2016 Sepsis-3 consensus definitions. Designed specifically for use outside the intensive care unit, it enables clinicians to identify patients with suspected infection who face an elevated risk of poor outcomes — including prolonged ICU admission and in-hospital mortality — using only three immediately observable clinical variables that require no laboratory testing.

The qSOFA Formula

The qSOFA score sums three binary clinical indicators:

qSOFA = 1[RR ≥ 22] + 1[AMS = 1] + 1[SBP ≤ 100]

Each condition that is present contributes exactly 1 point to the total. The minimum possible score is 0 and the maximum is 3. A score of ≥ 2 identifies patients at substantially higher risk for sepsis-related deterioration and warrants immediate further clinical evaluation and possible escalation of care.

Clinical Variables Explained

1. Respiratory Rate (RR ≥ 22 breaths/min)

An elevated respiratory rate is among the earliest physiological signals of systemic infection and impending organ dysfunction. A resting rate of 22 or more breaths per minute scores 1 point. The normal adult respiratory rate ranges from 12 to 20 breaths per minute, making a rate of 22 a clinically significant departure that warrants close observation in any patient with suspected infection.

2. Altered Mental Status (GCS < 15)

Any reduction in the Glasgow Coma Scale (GCS) below its maximum value of 15 indicates altered mental status and scores 1 point. This criterion captures confusion, lethargy, agitation, or any measurable change in level of consciousness. Even a GCS of 14 — reflecting mild disorientation — meets this threshold. In non-ICU settings where formal GCS calculation may be impractical, any observable change from the patient's neurological baseline should prompt scoring this criterion positive.

3. Systolic Blood Pressure (SBP ≤ 100 mmHg)

A systolic blood pressure of 100 mmHg or below signals hemodynamic compromise consistent with early septic shock physiology. Normal adult systolic blood pressure typically ranges between 90 and 120 mmHg; a reading at or below 100 mmHg in the context of suspected infection carries significant prognostic weight and necessitates urgent reassessment.

Score Interpretation

Score 0–1: Lower risk for organ dysfunction-related poor outcomes; continue standard clinical evaluation and monitor for clinical deterioration.
Score ≥ 2: High risk for sepsis-associated morbidity and mortality; initiate further sepsis workup, escalate care, and consider ICU referral. Research published in The Association of qSOFA, SOFA, and SIRS with Mortality in Emergency Patients demonstrates that a qSOFA ≥ 2 correlates with significantly higher in-hospital mortality rates among emergency department presentations.

Real-World Clinical Examples

Consider a 68-year-old patient presenting to the emergency department with suspected pneumonia. Vital signs show a respiratory rate of 24 breaths/min (1 point), systolic blood pressure of 95 mmHg (1 point), and a GCS of 14 due to mild confusion (1 point). The resulting qSOFA score of 3 demands immediate escalation: blood cultures, serum lactate measurement, and early broad-spectrum antibiotics, consistent with the UCSF Hospital Handbook Protocol for Septic Shock.

By contrast, a 45-year-old presenting with a urinary tract infection and vital signs of RR 17, SBP 122 mmHg, and GCS 15 scores 0, indicating a lower immediate risk profile and potentially supporting outpatient antibiotic management with close follow-up.

Limitations and Clinical Context

While the q sofa calculator is a powerful triage instrument, it should not replace comprehensive clinical judgment or the full SOFA score when resources permit. As noted in Current Utility of Sequential Organ Failure Assessment Score (PMC), qSOFA may exhibit lower sensitivity than SIRS criteria for early sepsis identification, meaning patients with early-stage sepsis may score below 2. A negative screen does not rule out sepsis. Optimal clinical practice integrates qSOFA with thorough history-taking, physical examination, and laboratory data for a complete risk assessment.

Reference

Frequently asked questions

What does a qSOFA score of 2 or higher mean?

A qSOFA score of 2 or higher indicates that a patient with suspected infection carries a high risk for poor outcomes, including organ failure, prolonged ICU admission, and in-hospital death. Clinicians should immediately initiate a full sepsis workup — blood cultures, serum lactate, and broad-spectrum antibiotics within one hour — while evaluating the patient for ICU-level monitoring and care escalation.

How is the qSOFA score different from the full SOFA score?

The qSOFA uses only three bedside variables — respiratory rate, altered mental status, and systolic blood pressure — requiring no laboratory tests, making it calculable in under one minute. The full SOFA score assesses six organ systems using lab values such as creatinine, bilirubin, platelet count, PaO2/FiO2 ratio, and vasopressor dosing. qSOFA is faster and more accessible; full SOFA provides greater prognostic depth but requires laboratory infrastructure.

Can the qSOFA score be used in pre-hospital or resource-limited settings?

Yes. The qSOFA score was explicitly designed for rapid bedside use without laboratory support, making it highly suitable for pre-hospital environments, urgent care clinics, rural hospitals, and resource-limited settings globally. Paramedics, nurses, and first responders can calculate it using a respiratory rate count, a manual blood pressure cuff, and a brief neurological check. A score of 2 or higher should prompt immediate transport to a higher level of care.

What is the maximum possible qSOFA score, and what does it indicate?

The maximum qSOFA score is 3, achieved when all three criteria are simultaneously present: respiratory rate at or above 22 breaths per minute, altered mental status defined as GCS below 15, and systolic blood pressure at or below 100 mmHg. A score of 3 represents the highest-risk profile and mandates immediate activation of sepsis management protocols, including fluid resuscitation, urgent antibiotics, and intensive care consultation.

How accurate is the qSOFA score for predicting sepsis-related mortality?

Published research shows that qSOFA has moderate-to-good predictive accuracy for in-hospital mortality in patients with suspected infection. Studies comparing qSOFA to SIRS criteria and Early Warning Scores indicate qSOFA outperforms SIRS for mortality prediction in emergency department populations. However, qSOFA carries lower sensitivity than SIRS for detecting all sepsis cases early, so it functions best as a rapid risk stratification tool used alongside full clinical assessment rather than as a standalone diagnostic.

What clinical actions should clinicians take after a positive qSOFA screen?

When qSOFA reaches 2 or more, clinicians should draw blood cultures before starting antibiotics, measure serum lactate to evaluate tissue perfusion, administer 30 mL/kg intravenous crystalloid if the patient is hypotensive, begin broad-spectrum antibiotics within one hour of sepsis recognition, and reassess organ function using the full SOFA score if ICU admission is being considered. Continuous vital sign monitoring and repeat qSOFA assessments guide ongoing resuscitation decisions.