Clinical predictors of pneumonia as a guide to ordering chest roentgenograms.

To develop criteria for a more efficient approach to the ordering of chest roentgenograms, patients with fever or respiratory symptoms who were being evaluated with this diagnostic test were prospectively monitored. During a six-month period, residents working in a pediatric emergency room collected data on 136 children, 3 months to 15 years of age. Pneumonia, defined by appropriate abnormal chest roentgenographic findings, occurred in 19 per cent. Of the 29 single symptoms or signs examined, the variable which was the best predictor of pneumonia was tachypnea. In addition, a cluster of pulmonary findings was also a good index, for pneumonia. If these clinical criteria had been applied to the patients under investigation, the number of chest roentgenograms obtained would have been reduced by 30 per cent.