Format

Send to

Choose Destination
CMAJ. 2017 Jan 16;189(2):E50-E55. doi: 10.1503/cmaj.151364. Epub 2016 Oct 24.

Predicting the presence of bacterial pathogens in the airways of primary care patients with acute cough.

Author information

1
Julius Center for Health Sciences and Primary Care (Teepe, Broekhuizen, Verheij), University Medical Center Utrecht, Utrecht, The Netherlands; Laboratory of Medical Microbiology, Vaccine and Infectious Disease Institute (VAXINFECTIO) (Loens, Lammens, Ieven, Goossens, Coenen), and Centre for General Practice, Primary and Interdisciplinary Care (Coenen), University of Antwerp, Antwerp, Belgium; Primary Care Medical Group (Little), University of Southampton Medical School, Southampton, UK; Nuffield Department of Primary Care Health Sciences (Butler), University of Oxford, Oxford, UK; Faculty of Health Sciences (Godycki-Cwirko), Medical University of Lodz, Lodz, Poland j.teepe-2@umcutrecht.nl.
2
Julius Center for Health Sciences and Primary Care (Teepe, Broekhuizen, Verheij), University Medical Center Utrecht, Utrecht, The Netherlands; Laboratory of Medical Microbiology, Vaccine and Infectious Disease Institute (VAXINFECTIO) (Loens, Lammens, Ieven, Goossens, Coenen), and Centre for General Practice, Primary and Interdisciplinary Care (Coenen), University of Antwerp, Antwerp, Belgium; Primary Care Medical Group (Little), University of Southampton Medical School, Southampton, UK; Nuffield Department of Primary Care Health Sciences (Butler), University of Oxford, Oxford, UK; Faculty of Health Sciences (Godycki-Cwirko), Medical University of Lodz, Lodz, Poland.

Abstract

BACKGROUND:

Bacterial testing of all patients who present with acute cough is not feasible in primary care. Furthermore, the extent to which easily obtainable clinical information predicts bacterial infection is unknown. We evaluated the diagnostic value of clinical examination and testing for C-reactive protein and procalcitonin for bacterial lower respiratory tract infection.

METHODS:

Through a European diagnostic study, we recruited 3104 adults with acute cough (≤ 28 days) in primary care settings. All of the patients underwent clinical examination, measurement of C-reactive protein and procalcitonin in blood, and chest radiography. Bacterial infection was determined by conventional culture, polymerase chain reaction and serology, and positive results were defined by the presence of Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Bordetella pertussis or Legionella pneumophila. Using multivariable regression analysis, we examined the association of diagnostic variables with the presence of bacterial infection.

RESULTS:

Overall, 539 patients (17%) had bacterial lower respiratory tract infection, and 38 (1%) had bacterial pneumonia. The only item with diagnostic value for lower respiratory tract infection was discoloured sputum (area under the receiver operating characteristic [ROC] curve 0.56, 95% confidence interval [CI] 0.54-0.59). Adding C-reactive protein above 30 mg/L increased the area under the ROC curve to 0.62 (95% CI 0.59-0.65). For bacterial pneumonia, comorbidity, fever and crackles on auscultation had diagnostic value (area under ROC curve 0.68, 95% CI 0.58-0.77). Adding C-reactive protein above 30 mg/L increased the area under the ROC curve to 0.79 (95% CI 0.71-0.87). Procalcitonin did not add diagnostic information for any bacterial lower respiratory tract infection, including bacterial pneumonia.

INTERPRETATION:

In adults presenting with acute lower respiratory tract infection, signs, symptoms and C-reactive protein showed diagnostic value for a bacterial cause. However, the ability of these diagnostic indicators to exclude a bacterial cause was limited. Procalcitonin added no clinically relevant information.

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center