Patient selection: serious infection (based on a diagnosis of acute infection by the ED physician AND hospital admission)
Clinical findings that can occur with a serious infection:
(1) systolic blood pressure < 100 mm Hg
(2) fever or suspicion of fever
(3) (respiratory rate > 20 breaths per minute) OR (pulse oximetry < 95%, presumably on room air)
(4) altered mental status
(5) heart rate > 90 beats per minute
Clinician suspicion of infection was not evaluated (this was a predictor in a prehospital tool in the same study).
50% of patients with a serious infection had 2 or more abnormal vital signs.
16% of patients had severe infection (based on admission to the ICU).
Limitations:
• The type of serious infections was not referenced to the clinical findings.
• The criteria for serious infection (ED physician diagnosis of infection AND hospital admission) might not be specific since a person could have been admitted for other reasons.
Performance:
• The most sensitive measures were heart rate, systolic blood pressure and altered mental status, which were all at 63%.
• The specificities ranged from 74% for heart rate to 94% for fever.
