Procalcitonin versus C-reactive protein for predicting pneumonia in adults with lower respiratory tract infection in primary care.

Abstract

Both procalcitonin >0.06 ng/ml and CRP > or =20 mg/l were associated with radiographic pneumonia, bacterial infection, and subsequent hospitalisation, but positive predictive values were too low for any of the two inflammatory markers to be of use in clinical practice. To measure procalcitonin values accurately in the primary care setting, a more sensitive method is needed, but there was no indication that procalcitonin is superior to CRP in identifying patients with pneumonia, bacterial aetiology, or adverse outcome.