Pneumonia severity scoring tools for CAP in adults

To assess the severity of CAP in adults, the Antibiotic Expert Group recommend using the features that may indicate hospital admission and the red flags for intensive care support rather than pneumonia severity scoring tools.

Pneumonia severity scoring tools, in conjunction with clinical judgement, may be used:

to decide whether to admit the patient to hospital (eg CRB-65 for primary care settings, CURB-65 and Pneumonia Severity Index [PSI] for emergency departmentsFine, 1997 Shirata, 2021)
to help identify patients at higher risk of death or requiring intensive care support (eg SMART-COPEhsanpoor, 2019, CORBReyes, 2022)
as a checklist of clinical features to review (eg SMART-COP).

However, these tools have limited sensitivity and specificity and aid clinical judgement rather than replace it. Pneumonia severity scoring tools are only relevant in the population for which they were developed; some studies in other populations reported poorer resultsTsai, 2022 Hincapie, 2021. Of note, CURB-65 and CRB-65 do not account for comorbidities and hypoxaemia; in younger patients (eg younger than 50 years) with hypoxaemia, pneumonia severity can be underestimated.

The choice of antibiotic therapy overlaps with scoring tools, but antibiotic therapy is determined by the likely pathogens. These scoring tools are not designed to suggest likely pathogens.