How accurate is the clinical diagnosis of pneumonia? (Clinical Inquiries).

* EVIDENCE-BASED ANSWER

No element or combination of elements from the clinical history and physical examination are sufficiently sensitive or specific to confirm or exclude acute community-acquired pneumonia (CAP). A chest x-ray is recommended to make the diagnosis (Grade of Recommendation: A, based on well-designed cohort studies). No studies specifically demonstrate improved patient outcomes through use of chest x-ray in adults; however, accurate diagnosis is expected to reduce the number of unnecessary antibiotic prescriptions (Grade of Recommendation: D, based on expert opinion).

* EVIDENCE SUMMARY

Metlay and colleagues (1) found only 4 high-quality, prospective cohort trials evaluating the sensitivity and specificity of the clinical history and physical examination in pneumonia. In each of the 4 studies, the reference standard for the diagnosis of pneumonia was a new infiltrate on chest radiograph. Subjects were community-dwelling adults with acute cough who were seen in ambulatory settings, and who had an average pneumonia prevalence of 7% (range, 3%-38%). (1) Although no study …