RT Journal Article SR Electronic T1 Predicting the presence of bacterial pathogens in the airways of primary care patients with acute cough JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP cmaj.151364 DO 10.1503/cmaj.151364 A1 Jolien Teepe A1 Berna D.L. Broekhuizen A1 Katherine Loens A1 Christine Lammens A1 Margareta Ieven A1 Herman Goossens A1 Paul Little A1 Chris C. Butler A1 Samuel Coenen A1 Maciek Godycki-Cwirko A1 Theo J.M. Verheij A1 GRACE Consortium YR 2016 UL http://www.cmaj.ca/content/early/2016/10/24/cmaj.151364.abstract AB 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 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.