SIRS Criteria vs qSOFA: Thresholds, Sepsis-3 and SEP-1

The SIRS criteria (2 or more of 4) flag systemic inflammation, but Sepsis-3 judged them nonspecific. qSOFA (2 or more of 3) prompts a search for organ dysfunction, and the 2026 Surviving Sepsis Campaign guideline advises against using it alone to screen.

What are the SIRS and qSOFA thresholds?

Score each tool item by item and call it positive at 2 or more. The Sepsis-3 paper (Box 1) lists both sets.

The 1992 ACCP/SCCM consensus conference introduced SIRS. The SIRS calculator scores the four items for you.

Why did Sepsis-3 move from SIRS to SOFA?

SIRS has inadequate specificity and sensitivity. Sepsis-3 (JAMA 2016) defines sepsis as life-threatening organ dysfunction from a dysregulated host response to infection, identified by an acute SOFA change of 2 points or more.

• SIRS is present in many hospitalized patients who never develop infection (Sepsis-3).
• About 1 in 8 critically ill patients with infection and new organ failure in Australia and New Zealand did not meet two SIRS criteria (Sepsis-3).
• A positive qSOFA should prompt a search for organ dysfunction and consideration of infection. A negative result should not defer investigation or treatment of infection (Sepsis-3).
• Neither qSOFA nor SOFA defines sepsis on its own. The SOFA calculator handles organ-system scoring.

What does the Surviving Sepsis Campaign say about qSOFA?

Skip qSOFA as a single screening tool for acutely ill hospitalized adults. The 2026 guideline strongly recommends NEWS, NEWS2, MEWS, or SIRS instead (moderate certainty), per the SCCM guideline page.

The guideline (Critical Care Medicine, March 2026, Prescott et al.) also recommends hospital sepsis performance improvement programs that screen acutely ill, high-risk patients. It states that no single biomarker or test should rule sepsis in or out. SCCM's adult guidelines page listed the 2026 document as current on 2026-10-10.

With known or suspected infection, the Royal College of Physicians working party recommends considering sepsis at a NEWS2 of 5 or more. In a 2001 cohort of 709 emergency medical admissions, a MEWS of 5 or higher carried higher odds of death, ICU admission, and HDU admission. The MEWS calculator scores it.

Why does CMS SEP-1 still use SIRS?

SEP-1 is a quality-reporting measure with its own abstraction rules, built on SIRS values and documented infection and organ dysfunction signs. Those rules sit outside the Sepsis-3 definition, so quality reporting and bedside definitions differ.

• The non-pregnant SIRS table in CMS's March 2023 webinar (manual v5.13) uses temperature above 38.3 or below 36.0 C, heart rate above 90, respiration above 20/min, and WBC above 12,000 or over 10% bands. The 38.3 C cutoff differs from the classic 38 C.
• Pregnant patients from 20 weeks through day 3 postpartum use a separate table.
• Physician, APN, or PA documentation of severe sepsis can also identify cases (same deck).
• QualityNet lists Specifications Manual v5.18a (2026 discharges) and v5.19 (2027 discharges). I confirmed the thresholds only in v5.13, so check the current manual before you build an abstraction workflow.

Where does this fall short?

The sources I opened give no sensitivity and specificity for each tool in your setting, and I did not verify pediatric or prehospital cutoffs. I reviewed the SCCM summary page, not the full Critical Care Medicine article, so read the full recommendation and its remarks before you write local policy. No single score diagnoses sepsis, and your result can differ by setting, population, and how reliably staff record the inputs.