Prediction of acute otitis media with symptoms and signs.

We carried out a prospective study to analyse if it would be possible to predict the coexistence of acute otitis media on the basis of symptoms and signs of infection. Of the 658 patients admitted to hospital during the period concerned, 197 (29.9%) had otitis media. For each child with otitis, the next patient of the same age was chosen as a control. The risk of having otitis media was increased among patients with cough, rhinitis and earache. All three variables together correctly classified 67% of those not having otitis media and 63% of those with acute otitis, compared with the 50% which would theoretically be achieved by chance alone. Prediction was worst (55%) among patients younger than 2 years of age not having otitis media and best among older patients who had otitis media, i.e. 78%. Prediction on these grounds would have caused significant over-treatment, and one-third of the otitis cases among the youngest group would have been missed. Thus it is important to always examine the ears of a child with an infection in order to reliably exclude the possibility of acute otitis media.