qSOFA (Quick SOFA) Calculator

How to Use This Calculator

1. Select Yes/No for each of the 3 qSOFA criteria.
2. Score (0–3) and sepsis risk recommendation display instantly.
3. qSOFA vs SIRS tab: compare both screening tools side by side.
4. Sepsis Bundle tab: integrates lactate and 1-hour bundle guidance.

Formula

Example

Frequently Asked Questions

• What is qSOFA and how is it different from SOFA? ▼
  The quick Sequential (Sepsis-related) Organ Failure Assessment (qSOFA) is a three-item bedside screening tool introduced in the Sepsis-3 consensus definitions published by Singer and colleagues in JAMA in 2016. It was designed for rapid identification of non-ICU patients with suspected infection who are at high risk for poor outcomes, defined as in-hospital mortality or prolonged ICU stay. The three qSOFA criteria are: respiratory rate ≥22 breaths per minute, altered mentation (defined as any GCS score below 15), and systolic blood pressure ≤100 mmHg. Each criterion scores 1 point (total 0–3). A score ≥2 identifies patients with high risk for poor outcomes and should prompt consideration of sepsis, escalation of care, and initiation of the sepsis management bundle. The full SOFA score is substantially more complex: it assesses six organ systems (respiratory, coagulation, liver, cardiovascular, central nervous system, renal) each scored 0–4, requiring laboratory values (PaO2/FiO2 ratio, platelets, bilirubin, creatinine, urine output) and vasopressor doses. In Sepsis-3, sepsis is formally defined as a suspected infection with acute organ dysfunction reflected by a ΔSOFA ≥2 from baseline. qSOFA is a screening trigger — not a diagnostic criterion — to prompt more detailed assessment including full SOFA calculation in relevant patients.
• When should qSOFA prompt full sepsis workup? ▼
  A qSOFA score ≥2 in a patient with known or suspected infection should immediately trigger a comprehensive sepsis assessment and initiation of the Surviving Sepsis Campaign Hour-1 Bundle. The five elements of the 1-hour bundle are: (1) measure blood lactate level (repeat if initial lactate >2 mmol/L); (2) obtain blood cultures before administering antibiotics; (3) administer broad-spectrum IV antibiotics; (4) begin rapid administration of 30 mL/kg crystalloid IV fluid for hypotension or lactate ≥4 mmol/L; (5) apply vasopressors (norepinephrine preferred) if patient is haemodynamically unstable during or after fluid resuscitation, targeting mean arterial pressure ≥65 mmHg. Simultaneously, a full SOFA score should be calculated to confirm organ dysfunction (ΔSOFA ≥2 = sepsis by Sepsis-3 definition). Source identification and control is critical: identify the infection focus (urine, chest, abdomen, skin/soft tissue, CNS), obtain appropriate cultures including urine, blood, sputum, and consider source control procedures (drainage, debridement, line removal) within 6–12 hours where indicated. A qSOFA score below 2 does not exclude sepsis — clinical judgement is essential. The Surviving Sepsis Campaign 2021 guidelines acknowledge that qSOFA has lower sensitivity than SIRS for detecting sepsis and should not be used as the sole sepsis trigger.
• Why was qSOFA developed instead of SIRS? ▼
  The Systemic Inflammatory Response Syndrome (SIRS) criteria — requiring ≥2 of: temperature >38.3°C or <36°C, heart rate >90 bpm, respiratory rate >20/min or PaCO2 <32 mmHg, and white blood cell count >12,000 or <4,000 or >10% bands — were introduced in the 1991 ACCP/SCCM consensus definition of sepsis. Over the subsequent 25 years, multiple studies demonstrated that SIRS criteria are highly sensitive but poorly specific for sepsis-associated poor outcomes: over 90% of general medical ward patients and a substantial proportion of post-surgical patients meet SIRS criteria at some point during their hospital stay, making the criteria practically useless for risk stratification. A 2015 JAMA study by Kaukonen et al. showed that one-eighth of patients with confirmed infection and organ failure (i.e., sepsis) did not meet SIRS criteria, while a large majority of SIRS-positive patients had no meaningful organ dysfunction. The Sepsis-3 task force therefore moved to replace SIRS as a sepsis trigger with qSOFA for out-of-ICU settings, emphasising organ dysfunction (SOFA ≥2) rather than the inflammatory response as the defining feature of sepsis. qSOFA was derived from a dataset of over 800,000 patients and validated independently. Its three items can be assessed without any laboratory tests, making it rapid and practical. The trade-off is lower sensitivity (~70%) compared to SIRS (~85%), but substantially higher specificity for mortality.
• Are there limitations of qSOFA in elderly? ▼
  qSOFA has several important limitations when applied to elderly patients. First, altered mentation is extremely common as a non-specific finding in hospitalised elderly patients due to pre-existing cognitive impairment, delirium from non-infectious causes (pain, medications, dehydration, unfamiliar environment), dementia, or post-operative confusion. Scoring GCS <15 as an automatic qSOFA point in elderly patients with baseline cognitive impairment may inappropriately elevate the score. Second, the systolic blood pressure threshold of ≤100 mmHg may be relatively common in frail elderly patients even without sepsis, particularly those on antihypertensive medications, diuretics, or patients with low baseline blood pressure. Third, baseline respiratory rate is higher in elderly patients with comorbidities such as COPD or heart failure, making RR ≥22 less discriminating as a sepsis marker in this population. Fourth, validation studies of qSOFA included relatively heterogeneous populations, and subgroup analyses in patients >75 years showed reduced discriminatory performance compared to middle-aged adults. Despite these limitations, qSOFA remains a useful rapid screening tool in the elderly when interpreted in clinical context — a score ≥2 should still trigger assessment but must be interpreted alongside the patient's baseline functional status and comorbidities. The National Early Warning Score 2 (NEWS2) has been proposed as an alternative sepsis screening tool with better performance in some elderly populations.
• Should qSOFA replace SIRS criteria? ▼
  The question of whether qSOFA should replace SIRS criteria for sepsis screening remains contested in critical care medicine. The Sepsis-3 definitions (Singer et al. JAMA 2016) proposed qSOFA as the preferred screening tool outside the ICU for identifying patients with suspected infection at high risk of poor outcomes. Multiple validation studies confirmed that qSOFA ≥2 outperforms SIRS ≥2 for predicting in-hospital mortality in non-ICU patients, with higher specificity (68% vs 31%) and better calibration for short-term mortality. However, a large systematic review and meta-analysis by Serafim et al. (2018) concluded that qSOFA has lower sensitivity (60% vs 88%) than SIRS for detecting sepsis by the Sepsis-3 definition, raising concern that using qSOFA alone would miss a substantial proportion of septic patients who require urgent treatment. The practical implication is that qSOFA is best used as a mortality risk stratification tool and rapid clinical trigger, not as a sensitive screening instrument for all cases of sepsis. The Surviving Sepsis Campaign 2021 guidelines recommend using qSOFA as a prompt for further assessment but explicitly state it should not replace comprehensive clinical evaluation or systematic early warning scoring systems (such as NEWS2, MEWS). Many hospitals retain SIRS-based sepsis alert systems for electronic health record automated screening (because SIRS criteria are easily extracted from vital signs and routine lab data), while using qSOFA for bedside clinical decisions.

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