TWO OF THE AUTHORS REPLY

We thank Gagliardi et al. (1) for their interest in our work and for the opportunity to present our data in more depth. Although our interpretations of results assessing antibiotic use and school-age wheeze (2) or asthma (3) may differ, we share a common concern about unnecessary antibiotic use in children. Our analyses (3) assessed the association between antibi-otic use before 6 months of age and physician-diagnosed asthma at 6 years of age with a special emphasis on the possible confounding role of ‘‘protopathic bias.’ ’ We in-cluded only children with physician-diagnosed asthma who had current wheeze at age 6 years and had their asthma first diagnosed after age 6 months. We observed that the associ-ation for antibiotic exposure was not attenuated in children without a history of lower respiratory tract infection or i