RT Journal Article
SR Electronic
T1 Procalcitonin versus C-reactive protein for predicting pneumonia in adults with lower respiratory tract infection in primary care
JF British Journal of General Practice
JO Br J Gen Pract
FD British Journal of General Practice
SP 555
OP 560
VO 57
IS 540
A1 Anette Holm
A1 Svend S Pedersen
A1 Joergen Nexoe
A1 Niels Obel
A1 Lars P Nielsen
A1 Ole Koldkjaer
A1 Court Pedersen
YR 2007
UL http://bjgp.org/content/57/540/555.abstract
AB Background The role of procalcitonin in diagnosing bacterial infection has mainly been studied in patients with severe infections. There is no study on the value of procalcitonin measurements in adults with lower respiratory tract infection (LRTI) treated in primary care.Aim To evaluate the accuracy of plasma procalcitonin in predicting radiographic pneumonia, bacterial infection, and adverse outcome in a population of adults with LRTI treated in primary care.Design of study Prospective, observational study.Setting Forty-two general practices and an outpatient clinic at the Department of Infectious Diseases, Odense University Hospital, Denmark.Method A total of 364 patients with LRTI were prospectively enrolled from 42 general practices. Patients were examined with chest radiography, microbiological analyses, and measurements of C-reactive protein (CRP) and procalcitonin. The outcome measure was hospitalisation within 4 weeks of enrolment.Results Median procalcitonin was 0.05 ng/ml, which was below the functional sensitivity of the assay (0.06 ng/ml). In predicting radiographic pneumonia, bacterial infection, and hospitalisation, the sensitivities of procalcitonin >0.06 ng/ml were 0.70, 0.51, and 0.67, and of CRP ≥20 mg/l were 0.73, 0.56, and 0.74 respectively. Corresponding positive predictive values were between 0.09 and 0.28.Conclusion Both procalcitonin >0.06 ng/ml and CRP ≥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.