qSOFA Score Calculator

What is qSOFA?

The quick Sequential Organ Failure Assessment (qSOFA) score was introduced in 2016 as part of the Sepsis-3 consensus definitions. It is designed as a rapid bedside screening tool that uses three simple clinical criteria — none of which require laboratory testing — to identify patients with suspected infection who are at greater risk of poor outcomes including prolonged ICU stay or death.

Unlike the full SOFA score which requires laboratory values, qSOFA can be performed in seconds at the bedside, making it ideal for emergency departments, general wards, and pre-hospital settings.

Scoring Criteria

Criterion	Threshold	Points
Respiratory rate	≥ 22 breaths/min	1
Systolic blood pressure	≤ 100 mmHg	1
Altered mental status	GCS < 15	1

Score Interpretation

qSOFA Score	Risk Level	In-Hospital Mortality	Action
0	Low risk	< 3%	Standard care; monitor
1	Low risk	~3%	Re-evaluate; consider monitoring
≥ 2	High risk	> 10%	Assess for organ dysfunction (full SOFA); consider ICU
3	Very high risk	> 20%	Urgent escalation; full sepsis workup

qSOFA Decision Flowchart

Sepsis-3 Definition

The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3), published in 2016 in JAMA, redefined sepsis as "life-threatening organ dysfunction caused by a dysregulated host response to infection." This replaced the previous definition that relied on the Systemic Inflammatory Response Syndrome (SIRS) criteria.

Under Sepsis-3:

• Sepsis is defined as suspected or confirmed infection with an acute increase in SOFA score ≥ 2 points (representing organ dysfunction)
• Septic shock is a subset of sepsis with circulatory and cellular/metabolic dysfunction: persistent hypotension requiring vasopressors to maintain MAP ≥ 65 mmHg AND serum lactate > 2 mmol/L despite adequate volume resuscitation
• The qSOFA serves as a bedside prompt to further evaluate for organ dysfunction, not as a definition of sepsis itself

qSOFA vs SIRS

The SIRS criteria (temperature >38°C or <36°C, heart rate >90, respiratory rate >20, WBC >12,000 or <4,000) were previously used to identify sepsis. However, SIRS had significant limitations:

Feature	qSOFA	SIRS
Number of criteria	3	4
Lab tests required	No	Yes (WBC)
Positive threshold	≥ 2 of 3	≥ 2 of 4
Specificity for poor outcomes	Higher	Lower
Sensitivity for sepsis	Lower	Higher
Best setting	Outside ICU (ward, ED)	Any setting
Purpose	Prognostic screening	Inflammatory response detection

A key criticism of qSOFA is its lower sensitivity compared to SIRS, meaning some septic patients with qSOFA < 2 may be missed. Current guidelines recommend using qSOFA as a screening tool, not as a standalone diagnostic criterion. Clinical judgment remains paramount.

Sepsis Management

When sepsis is suspected based on qSOFA ≥ 2 and confirmed by organ dysfunction assessment, the Surviving Sepsis Campaign recommends the following Hour-1 Bundle:

1. Measure lactate level — re-measure if initial lactate > 2 mmol/L
2. Obtain blood cultures before administering antibiotics
3. Administer broad-spectrum antibiotics — ideally within 1 hour of recognition
4. Begin rapid IV fluid resuscitation — 30 mL/kg crystalloid for hypotension or lactate ≥ 4 mmol/L
5. Apply vasopressors if hypotensive during or after fluid resuscitation (target MAP ≥ 65 mmHg)

Worked Example

A 72-year-old patient presents to the emergency department with fever and productive cough. Vitals: respiratory rate 26/min, blood pressure 88/52 mmHg, heart rate 110 bpm, GCS 14 (mildly confused).

With a qSOFA of 3, this patient is at very high risk (>20% in-hospital mortality). Immediate actions: obtain blood cultures, measure lactate, start broad-spectrum antibiotics, begin 30 mL/kg IV crystalloid bolus, and assess full SOFA score. Consider ICU admission.

Frequently Asked Questions

Is qSOFA used to diagnose sepsis?

No. qSOFA is a screening tool to identify patients with suspected infection who may have sepsis. A positive qSOFA (≥2) should prompt further evaluation for organ dysfunction using the full SOFA score, laboratory testing, and clinical assessment. The diagnosis of sepsis requires evidence of organ dysfunction, not just a positive qSOFA.

Can qSOFA be used in the ICU?

qSOFA was developed and validated primarily for use outside the ICU (emergency department, general ward, pre-hospital). In the ICU, the full SOFA score is more appropriate for assessing organ dysfunction because ICU patients often already meet qSOFA criteria due to their baseline illness severity.

What if qSOFA is 0-1 but I still suspect sepsis?

A negative qSOFA does not rule out sepsis. If clinical suspicion remains high, proceed with full sepsis evaluation including lactate measurement, blood cultures, and SOFA assessment. qSOFA has moderate sensitivity, meaning some septic patients will be missed by this screening tool alone.

How often should qSOFA be reassessed?

In patients with suspected infection, qSOFA should be reassessed with each set of vital signs or whenever there is a clinical change. A patient who initially scores 0-1 may deteriorate and later meet the threshold of ≥2.