Diagnostic Value of Chest X-Ray in Febrile Patients without Localizing Signs or Symptoms at the Emergency Department

Background: The chest X-ray (CXR) remains a widely used examination in the evaluation of patients with fever, to diagnose or rule out pneumonia. Recently, a study by our group suggested that it has no diagnostic value in patients with fever without respiratory signs and/or symptoms. Objective: The objective of this study is to validate the results of our previous study. Design: A retrospective study was conducted in two hospitals in the Netherlands. Patients: All patients that were referred to the internal medicine emergency department between May 2018 and May 2019 with a suspected infection defined as fever (temperature >= 38 degrees C) or hypothermia (temperature <36 degrees C) or CRP >= 100 mu g/mL. Main Measures: We defined our primary outcome as the number of newly diagnosed pneumonia by CXR in cases of suspected infection with no obvious site of infection and nor localizing symptoms or signs. Key Results: We included 1052 patients, of which 106 did not have respiratory signs or symptoms. In this group, none of the CXRs (95% CI 0-2.36%) showed an infiltrate. Combined with our previous study, 176 CXRs were performed in patients with no respiratory signs or symptoms. None (95% CI 0-1.42%) showed an infiltrate.