Clinical signs of pneumonia in children.

Clinical and chest radiographic findings were recorded prospectively in 185 children with cough who attended an outpatient clinic in Papua New Guinea. Children were studied if they were between 8 weeks and 6 years of age; patients with wheeze, stridor, measles, or pertussis were excluded. 56 children (30%) had radiological evidence of pneumonia. The presence of either a respiratory rate greater than or equal to 50/min or chest indrawing, or of both signs, was a good indication of pneumonia, with a predictive power of 46% for a positive test and 83% for a negative test. A more complex definition of tachypnoea, as a respiratory rate greater than or equal to 40/min in children over 12 months old and greater than or equal to 50/min in infants, showed little additional diagnostic benefit.