qSOFA Score Calculator
Quickly compute the qSOFA score from respiratory rate, systolic blood pressure and mental status to screen for sepsis risk in patients with suspected infection. Enter the three bedside values and get the score and risk category instantly.
Check Sepsis Risk from Respiratory Rate, Blood Pressure and Mental Status
qSOFA Score Formula
Where:
- \(RR\) — respiratory rate in breaths per minute; 1 point if \(RR \ge 22\)
- \(SBP\) — systolic blood pressure in mmHg; 1 point if \(SBP \le 100\)
- \(GCS\) — Glasgow Coma Scale; 1 point for any acute altered mentation, i.e. \(GCS < 15\)
- \(\mathbb{1}(\cdot)\) — indicator function, equal to 1 when the condition is true and 0 otherwise
The formula adds one point for each of the three bedside criteria that is met, giving a total score from 0 to 3. A score of 2 or more flags a higher risk of poor outcomes in patients with suspected infection.
qSOFA Score – Calculation Example
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Example: a patient with suspected infection has a respiratory rate of 24 breaths/min, a systolic blood pressure of 95 mmHg and is confused (GCS below 15).
\[ \mathbb{1}(24 \ge 22) + \mathbb{1}(95 \le 100) + \mathbb{1}(GCS < 15) = 1 + 1 + 1 = 3 \]
Result: qSOFA score = 3 of 3, which falls into the higher-risk category (qSOFA ≥ 2). All three criteria are met, so the patient should be assessed promptly for possible sepsis.
{/example}
How to Use the qSOFA Calculator
- Enter the patient's Respiratory rate in breaths per minute (1–80).
- Enter the Systolic blood pressure in mmHg (20–300).
- Select whether there is Altered mental status: choose "Yes (GCS below 15, any confusion)" for any acute change in mentation, or "No (GCS 15, fully alert)" if the patient is fully alert.
- Read the qSOFA score (0–3), the Risk category and the interpretation of each criterion in the result panel.
What Is the qSOFA Score?
The quick Sequential Organ Failure Assessment (qSOFA) is a bedside screening tool introduced by the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3, Singer et al., JAMA 2016). It was designed to help clinicians identify, without any laboratory tests, which patients with suspected infection are at higher risk of a poor outcome, such as prolonged ICU stay or in-hospital mortality.
The score uses three simple criteria: a respiratory rate of 22 breaths/min or faster, a systolic blood pressure of 100 mmHg or lower, and any acute alteration in mental status. Each criterion that is met adds one point. All three can be assessed within minutes at the bedside or even in a pre-hospital setting, which is exactly what makes the tool useful for early triage.
A qSOFA score of 2 or more should prompt further evaluation for organ dysfunction — typically a full SOFA score, blood cultures, lactate measurement and, when sepsis is suspected, early treatment following local protocols. A score below 2 indicates lower risk, but it does not rule out sepsis: qSOFA is a risk screen, not a diagnostic test. If clinical concern persists despite a low score, additional workup is still appropriate.
If you need to assess the mental status criterion in detail, the Glasgow Coma Scale calculator helps determine the exact GCS. For patients with pneumonia, the CURB-65 score is a related bedside tool that estimates severity and mortality risk, and the mean arterial pressure calculator can give a fuller picture of hemodynamic status.
Limitations and Practical Notes
- Not a diagnosis. qSOFA identifies patients at higher risk of poor outcomes; it does not diagnose sepsis. Sepsis is defined by suspected infection plus organ dysfunction measured by the full SOFA score, which requires laboratory data.
- Lower sensitivity in some settings. Later analyses showed qSOFA is more specific than sensitive — a low score does not exclude sepsis, especially in older patients or those on medications that mask tachypnea or hypotension (e.g. beta-blockers).
- Acute change matters. The mental status criterion refers to any acute change from the patient's baseline. Chronic confusion (e.g. dementia) without acute worsening does not count as altered mentation.
- Apply only when infection is suspected. The score is validated for patients with suspected infection; using it in unselected patients leads to misleading results.
- Single time point. Values can change quickly. Repeating the assessment over time is often more informative than a single measurement.
- This calculator is for informational and educational purposes only and is not a substitute for professional medical judgment.
qSOFA Criteria Reference Table
| Criterion | Threshold | Points |
|---|---|---|
| Respiratory rate (RR) | ≥ 22 breaths/min | 1 |
| Systolic blood pressure (SBP) | ≤ 100 mmHg | 1 |
| Altered mental status (GCS) | GCS < 15 / acute change | 1 |
Total score ranges from 0 to 3. A score of 2 or more (≥ 2) indicates higher risk and should trigger further sepsis evaluation; a score of 0 or 1 indicates lower risk but does not exclude infection or sepsis.
Frequently Asked Questions
How do I calculate the qSOFA score by hand?
Check three bedside criteria and add 1 point for each one that is met: respiratory rate of 22 breaths/min or higher, systolic blood pressure of 100 mmHg or lower, and any acute change in mental status (GCS below 15). The total ranges from 0 to 3. For example, a patient breathing at 24/min with a normal blood pressure of 120 mmHg and full alertness scores 1 + 0 + 0 = 1.
What is a normal or concerning qSOFA score?
The scale runs from 0 to 3. A score of 0 or 1 is considered lower risk for poor outcomes such as prolonged ICU stay or in-hospital mortality. A score of 2 or 3 indicates higher risk and should prompt prompt further evaluation for sepsis, including a full SOFA assessment, lactate measurement and blood cultures. Keep in mind that even a score of 0 does not rule out sepsis — it is a risk screen, not a diagnosis.
Is qSOFA still recommended for screening sepsis?
Guidelines have evolved since Sepsis-3 introduced qSOFA in 2016. The Surviving Sepsis Campaign 2021 guidelines recommend against using qSOFA as a single screening tool because of its low sensitivity — many patients with sepsis score below 2. Many hospitals now use combined tools such as SIRS criteria together with qSOFA or the National Early Warning Score (NEWS2). A high qSOFA remains a useful red flag; a low one should never provide reassurance on its own.
What GCS value counts as altered mental status?
Any Glasgow Coma Scale value below 15 counts, which corresponds to any acute change from the patient's baseline — confusion, agitation, drowsiness or obtundation. Importantly, the change must be acute: chronic confusion from dementia without acute worsening does not earn the point. If you are unsure of the exact GCS, the Glasgow Coma Scale calculator can help you score eye, verbal and motor responses precisely.
Can I use qSOFA if blood pressure or respiratory values were measured in other units?
The thresholds are defined as 22 breaths/min for respiratory rate and 100 mmHg for systolic blood pressure, so convert your values first. For example, 100 mmHg equals about 13.3 kPa. If blood pressure is given in kPa, multiply by 7.5 to get mmHg before entering it. Respiratory rate is simply counted over one minute (or over 30 seconds and doubled).
Does a patient on beta-blockers or with chronic lung disease get scored differently?
No, the criteria stay the same, but interpretation needs caution. Beta-blockers can blunt tachycardia and tachypnea, and some patients chronically run low blood pressure, so the score may underestimate risk. Conversely, patients with COPD may have an elevated baseline respiratory rate. This is a known limitation of qSOFA — it is more specific than sensitive, so clinical judgment and repeat measurements over time are essential.
qSOFA vs. SOFA vs. SIRS — what is the difference?
qSOFA is a quick bedside screen using only respiratory rate, blood pressure and mental status — no labs needed. The full SOFA score requires laboratory data (platelets, bilirubin, creatinine, PaO2) and defines organ dysfunction; sepsis is suspected infection plus a SOFA increase of 2 or more. SIRS criteria (temperature, heart rate, respiratory rate, white blood cells) are older and more sensitive but less specific. qSOFA is best treated as an early warning sign rather than a stand-alone diagnostic test.