Parsing Pneumonia: Dual Definitions of Severe CABP Reveal Overlapping Risks and High Mortality

journals.lww.com June 20, 2026

This study analyzed 67,439 patients diagnosed with severe community-acquired bacterial pneumonia (sCABP)—representing nearly a quarter of all CAPB admissions—to compare two major clinical definitions: ICU-sCABP (51.2% of the cohort) and ATS-sCABP (78.0% of the cohort).

The analysis revealed that despite differing criteria, both definitions identify highly similar patient populations in terms of demographics, underlying chronic illnesses, pathogen distribution, and treatment courses.

Ultimately, both groups represent a heavy burden on healthcare resources and face a similarly stark mortality risk.

Identical Patient Profiles: Patients meeting either definition showed no significant differences in age, gender, race, or baseline chronic comorbidities.

An Evolution in Ventilation: Post-pandemic mechanical ventilation (MV) practices have evolved significantly, shifting heavily toward non-invasive positive pressure ventilation (used in 27.9% of ICU-sCABP and 65.6% of ATS-sCABP patients).

Invasive MV (IMV) has dropped in popularity, utilized in fewer than 25% of patients in either group.

Whether categorized by ICU status or ATS criteria, sCABP identifies a large, highly resource-intensive population. While ventilation strategies have shifted drastically away from invasive intubation, the overall risk of death remains unacceptably high, demanding continued therapeutic innovation.