qSOFA Calculator

Q: What are the 3 qSOFA criteria?

The three qSOFA criteria are a respiratory rate of 22 breaths per minute or higher, altered mentation (a Glasgow Coma Scale score below 15), and a systolic blood pressure of 100 mmHg or lower. Each criterion present adds 1 point, for a total score of 0 to 3.

Q: What is the qSOFA positive-screen cutoff?

A qSOFA score of 2 or higher is considered screen-positive. It identifies patients outside the ICU who are at greater risk of a poor outcome and should prompt further sepsis assessment, such as measuring lactate and considering the full SOFA score or Sepsis-3 criteria.

Q: How is qSOFA different from SIRS criteria?

SIRS (Systemic Inflammatory Response Syndrome) criteria use temperature, heart rate, respiratory rate, and white blood cell count, and were the prior standard for flagging possible sepsis. qSOFA replaced SIRS as the recommended bedside screen under the Sepsis-3 definitions because it better predicted in-hospital mortality outside the ICU using only three criteria that require no laboratory tests.

Q: How does qSOFA differ from the full SOFA score?

The full SOFA (Sequential Organ Failure Assessment) score evaluates six organ systems using laboratory values such as bilirubin, creatinine, and platelet count, and is used to formally define sepsis in ICU settings. qSOFA is a simplified, lab-free bedside version of only three criteria, designed for rapid screening outside the ICU — such as in the emergency department or on a general ward — where full SOFA data is not immediately available.

Q: Where is qSOFA meant to be used?

qSOFA is intended for use outside the intensive care unit — for example in the emergency department, on general hospital wards, or in pre-hospital settings — to quickly flag patients with suspected infection who may be at higher risk of a poor outcome and warrant closer monitoring or further workup.

Q: What are the sensitivity limitations of qSOFA?

qSOFA prioritizes specificity over sensitivity: studies have found it misses a meaningful proportion of patients who go on to have sepsis-related complications, particularly early in their presentation. A negative qSOFA screen does not rule out sepsis, and clinical judgment should always override a reassuring score if infection is still suspected.

qSOFA Score	Interpretation	Typical Guidance
≥ 2 (screen positive)	Suggests higher risk of poor outcome	Consider sepsis workup, lactate measurement, and closer monitoring or escalation
< 2 (screen negative)	Does not flag increased risk on qSOFA alone	Continue routine monitoring; reassess if the patient deteriorates or infection is still suspected

	qSOFA	Full SOFA
Criteria	3 bedside signs	6 organ systems
Labs required	None	Bilirubin, creatinine, platelets, and more
Typical setting	Emergency department, general ward, pre-hospital	Intensive care unit
Speed	Seconds, at the bedside	Requires lab turnaround
Role	Rapid screening trigger	Formal organ-dysfunction scoring for sepsis definition
Score range	0–3	0–24

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Walk-through

How to Use This Calculator

3 steps

1

Check every criterion present at the bedside

Check the box for each of the three qSOFA criteria the patient currently meets: respiratory rate 22 breaths per minute or higher, altered mentation (a Glasgow Coma Scale score below 15), and systolic blood pressure 100 mmHg or lower. The score updates instantly as you check each box.

2

Read the score and risk signal

The qSOFA Score tab shows the total (0 to 3) and a plain-language risk signal. A score of 2 or higher is screen-positive and suggests a higher risk of a poor outcome; a score below 2 does not flag increased risk on qSOFA alone.

3

Review the interpretation and comparison to full SOFA

Switch to the Interpretation tab to see what the >= 2 threshold means for your point breakdown, or the vs Full SOFA tab to understand how this fast bedside screen relates to the lab-based full SOFA score used in the ICU.

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Reference

Formula & Methodology

4 formulas

qSOFA score (total)

qSOFA = respiratory rate + altered mentation + systolic BP (each 0 or 1)

The total is a simple sum of three binary criteria, each worth 1 point when present. The range runs from 0 (no criteria met) to 3 (all three criteria met). No laboratory values are required.

Respiratory rate criterion

Respiratory rate >= 22 breaths/min -> +1 point

A respiratory rate at or above 22 breaths per minute reflects the body's compensatory response to a physiologic insult such as infection, and is one of the three criteria most predictive of poor outcomes in patients with suspected infection outside the ICU.

Altered mentation criterion

Glasgow Coma Scale (GCS) < 15 -> +1 point

Any deviation from a normal GCS of 15 — including drowsiness, confusion, or reduced responsiveness — counts as altered mentation. It does not require a specific lower GCS threshold beyond less-than-15.

Systolic blood pressure criterion

Systolic BP <= 100 mmHg -> +1 point

A systolic blood pressure at or below 100 mmHg reflects potential hypoperfusion and is the third of the three qSOFA criteria.

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High YMYL

Trust, Methodology & Sources

Reviewed by Calculover Editorial Review · Updated 2026-07-22 · 2 sources

Editorial accountability

Author: Quinn Sumner - Editor

Owner: Quinn Sumner - Editorial owner

Reviewer: Calculover Editorial Review - Clinical-source review

Last reviewed: 2026-07-22

Last verified: 2026-07-22

Data effective: 2026-07-22

Methodology

The calculator implements qSOFA exactly as published in the Sepsis-3 consensus definitions (Singer M, Deutschman CS, Seymour CW, et al., JAMA 2016;315(8):801-810) — three binary bedside criteria (respiratory rate, altered mentation, systolic blood pressure), each worth 1 point, summed to a total ranging from 0 to 3, with a score of 2 or higher indicating a screen-positive result associated with higher risk of a poor outcome.

Assumption: The patient has suspected or confirmed infection and is being assessed outside the intensive care unit, matching the population qSOFA was designed to screen.

Assumption: All three criteria (respiratory rate, mentation status, and systolic blood pressure) are assessed accurately and reflect the patient's current bedside status.

Limitations & guidance

qSOFA is a screening tool, not a diagnostic criterion for sepsis — it does not itself confirm or rule out sepsis, and the formal Sepsis-3 diagnosis still requires evidence of organ dysfunction.

qSOFA prioritizes specificity over sensitivity and has known limitations in detecting sepsis-related risk early in a patient's presentation; a negative screen should not be used alone to exclude sepsis.

qSOFA was designed for use outside the ICU; in an ICU setting with laboratory data already available, the full SOFA score is the more appropriate and validated tool.

Professional guidance: This calculator is for education only and is not medical advice, diagnosis, or treatment. qSOFA is a bedside screening tool, not a sepsis diagnosis, and does not replace the judgment of a licensed clinician evaluating the full clinical picture.

Primary sources

The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) (Singer M et al., JAMA 2016)

MDCalc — qSOFA (Quick SOFA) Score for Sepsis

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Glossary

Key Terms Explained

7 terms

qSOFA (quick SOFA) A 3-criterion bedside score (range 0-3) that screens for a higher risk of poor outcomes in patients with suspected infection outside the intensive care unit, without requiring laboratory tests.

Sepsis-3 The Third International Consensus Definitions for Sepsis and Septic Shock (Singer et al., JAMA 2016), which redefined sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection and introduced qSOFA as a bedside screening tool.

Altered mentation Any reduction from a normal Glasgow Coma Scale score of 15 — including confusion, drowsiness, or decreased responsiveness — counted as present for qSOFA regardless of the specific lower GCS value.

SOFA score The Sequential Organ Failure Assessment score, a 6-organ-system, laboratory-based score (range 0-24) used to formally define sepsis-related organ dysfunction, typically in an ICU setting.

Sepsis screening The process of rapidly identifying patients with suspected infection who may be at higher risk of a poor outcome, so that further evaluation (such as lactate measurement or full SOFA scoring) and treatment can begin promptly.

ICU vs ward use qSOFA is designed for use outside the intensive care unit — in the emergency department, on a general ward, or in pre-hospital settings — where the laboratory data needed for the full SOFA score is not immediately available.

Glasgow Coma Scale (GCS) A 15-point neurological scale assessing eye-opening, verbal, and motor responses; a score below 15 indicates some degree of altered consciousness and satisfies the qSOFA mentation criterion.

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Scenarios

Real-World Examples

3 worked examples

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Patient with normal vitals and suspected infection

qSOFA 0 — screen negative

Respiratory rate ≥ 22/min No Altered mentation (GCS < 15) No Systolic BP ≤ 100 mmHg No

None of the three criteria are met, for a total qSOFA score of 0. This does not flag increased risk of a poor outcome on qSOFA alone — routine monitoring continues, though a negative screen does not rule out sepsis if infection is still clinically suspected.

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Patient with a fast breathing rate and low blood pressure

qSOFA 2 — screen positive

Respiratory rate ≥ 22/min Yes Altered mentation (GCS < 15) No Systolic BP ≤ 100 mmHg Yes

Respiratory rate and low systolic blood pressure each contribute 1 point, for a total qSOFA score of 2. This meets the screen-positive threshold and suggests a higher risk of a poor outcome — a sepsis workup, lactate measurement, and closer monitoring should be considered.

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Confused patient with rapid breathing and hypotension

qSOFA 3 — maximum score

Respiratory rate ≥ 22/min Yes Altered mentation (GCS < 15) Yes Systolic BP ≤ 100 mmHg Yes

All three criteria are met, for the maximum qSOFA score of 3. This is well above the screen-positive threshold of 2 and warrants prompt sepsis evaluation and escalation of care, in addition to the clinician's overall assessment of the patient.

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Deep Dive

Understanding the qSOFA Calculator

3 chapters · 4 min read

qSOFA (quick SOFA) is a fast, lab-free bedside score introduced by the Sepsis-3 consensus definitions to help clinicians outside the ICU — in the emergency department, on a general ward, or in pre-hospital settings — quickly flag patients with suspected infection who may be at higher risk of a poor outcome. This calculator sums the three qSOFA criteria into a 0-3 score and explains what the result means.

How the qSOFA score works

qSOFA sums three binary bedside criteria, each worth 1 point when present: a respiratory rate of 22 breaths per minute or higher, altered mentation (a Glasgow Coma Scale score below 15), and a systolic blood pressure of 100 mmHg or lower. The resulting total ranges from 0 to 3 and requires no laboratory tests, making it fast to apply at first contact with a patient.

The score was derived and validated by analyzing which combination of easily obtained bedside signs best predicted in-hospital mortality and prolonged ICU stay among patients with suspected infection outside the intensive care unit.

Reading the threshold

A qSOFA score of 2 or higher is considered screen-positive: in the derivation and validation cohorts, patients meeting this threshold had a substantially higher risk of a poor outcome than those scoring below 2. A positive screen should prompt further evaluation — such as lactate measurement, blood cultures, and consideration of the full SOFA score — rather than serve as a sepsis diagnosis on its own.

A score below 2 does not flag increased risk on qSOFA alone, but it does not rule out sepsis. Clinical judgment should always override a reassuring score if infection is still suspected.

Limits and how it should be used

qSOFA is a screening tool, not a diagnostic criterion for sepsis — the formal Sepsis-3 definition of sepsis still requires evidence of organ dysfunction, typically assessed with the full SOFA score. qSOFA prioritizes specificity over sensitivity, meaning it can miss a meaningful proportion of patients who go on to develop sepsis-related complications, particularly early in their presentation. It is intended for use outside the ICU; in an ICU setting where laboratory data is already available, the full SOFA score is the more appropriate tool. This calculator is for education and clinical decision support only — it does not replace the treating clinician's judgment.

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Questions

Frequently Asked Questions

6 questions

What are the 3 qSOFA criteria?+

The three qSOFA criteria are a respiratory rate of 22 breaths per minute or higher, altered mentation (a Glasgow Coma Scale score below 15), and a systolic blood pressure of 100 mmHg or lower. Each criterion present adds 1 point, for a total score of 0 to 3.

What is the qSOFA positive-screen cutoff?+

A qSOFA score of 2 or higher is considered screen-positive. It identifies patients outside the ICU who are at greater risk of a poor outcome and should prompt further sepsis assessment, such as measuring lactate and considering the full SOFA score or Sepsis-3 criteria.

How is qSOFA different from SIRS criteria?+

SIRS (Systemic Inflammatory Response Syndrome) criteria use temperature, heart rate, respiratory rate, and white blood cell count, and were the prior standard for flagging possible sepsis. qSOFA replaced SIRS as the recommended bedside screen under the Sepsis-3 definitions because it better predicted in-hospital mortality outside the ICU using only three criteria that require no laboratory tests.

How does qSOFA differ from the full SOFA score?+

The full SOFA (Sequential Organ Failure Assessment) score evaluates six organ systems using laboratory values such as bilirubin, creatinine, and platelet count, and is used to formally define sepsis in ICU settings. qSOFA is a simplified, lab-free bedside version of only three criteria, designed for rapid screening outside the ICU — such as in the emergency department or on a general ward — where full SOFA data is not immediately available.

Where is qSOFA meant to be used?+

qSOFA is intended for use outside the intensive care unit — for example in the emergency department, on general hospital wards, or in pre-hospital settings — to quickly flag patients with suspected infection who may be at higher risk of a poor outcome and warrant closer monitoring or further workup.

What are the sensitivity limitations of qSOFA?+

qSOFA prioritizes specificity over sensitivity: studies have found it misses a meaningful proportion of patients who go on to have sepsis-related complications, particularly early in their presentation. A negative qSOFA screen does not rule out sepsis, and clinical judgment should always override a reassuring score if infection is still suspected.

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Bedside Criteria

qSOFA Score & Risk Signal

Your Point Breakdown

What Your Score Means

qSOFA vs the Full SOFA Score

How to Use This Calculator

Check every criterion present at the bedside

Read the score and risk signal

Review the interpretation and comparison to full SOFA

Formula & Methodology

Trust, Methodology & Sources

Key Terms Explained

Real-World Examples

Patient with normal vitals and suspected infection

Patient with a fast breathing rate and low blood pressure

Confused patient with rapid breathing and hypotension

Understanding the qSOFA Calculator

How the qSOFA score works

Reading the threshold

Limits and how it should be used

Frequently Asked Questions

Get a branded PDF of your results

qSOFA Calculator

Bedside Criteria

qSOFA Score & Risk Signal

Your Point Breakdown

What Your Score Means

qSOFA vs the Full SOFA Score

How to Use This Calculator

Check every criterion present at the bedside

Read the score and risk signal

Review the interpretation and comparison to full SOFA

Formula & Methodology

Trust, Methodology & Sources

Key Terms Explained

Real-World Examples

Understanding the qSOFA Calculator

How the qSOFA score works

Reading the threshold

Limits and how it should be used

Frequently Asked Questions

Get a branded PDF of your results

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