Respiratory rate greater than 50 per minute as a clinical indicator of pneumonia in Filipino children with cough.

The diagnosis and epidemiology of acute respiratory tract infection (ARI) in 199 children less than 5 years old were investigated in Manila. As part of this study, children who were treated at one of two outpatient clinics for cough of less than 3 weeks' duration were studied to test the validity of the use of a respiratory rate (RR) of greater than 50/minute for identifying ARI of a severity necessitating treatment with antibiotics. In the first population, in which 69% of the children had radiologically confirmed pneumonia, the sensitivity of a RR of greater than 50/minute was 54%, the specificity was 84%, the false-positive rate was 16%, and the false-negative rate was 46%. In the second population, in which 29% of the children had pneumonia, the sensitivity and positive predictive values were low. The validity of a RR of greater than 50/minute may vary in populations with different prevalences of ARI.