After assessing the clinical probability of pneumonia, CRP levels will be provided for a random subset of patients. A CRP level <10 mg/L corresponds with a very low probability of bacterial pneumonia. Thus, for patients with low and intermediate-probability of pneumonia based on clinical grounds, a CRP <10 mg/L should confirm that no CXR or antibiotics are necessary in routine cases (See attached algorithm). A CRP level > 100 mg/L corresponds with a substantially elevated probability of pneumonia. Thus, for patients with low and intermediate-probability of pneumonia based on clinical grounds, a CRP >100 mg/L would support CXR ordering, and for patients with high clinical suspicion, antibiotic therapy should be considered regardless of the CXR result (since studies show that CXR misses about 10% of community-acquired pneumonia confirmed with follow-up CXR or chest computed tomography). Overall, the addition of CRP test results would reduce the need for CXR ordering and antibiotic therapy in cases with an intermediate clinical probability of pneumonia and a low CRP level; and increase the need for CXR ordering and possibly antibiotic therapy in cases with intermediate or high clinical probability of pneumonia and a high CRP level. In this way, we hypothesize that the CRP-guided management algorithm will improve the proportion of patients with acute cough illness who receive appropriate diagnostic and therapeutic interventions in the ED.