In outlining the development and course of asthma in children it is important to emphasize that, although asthma is a common illness, it is not a reportable one, and therefore its true incidence is unknown and can only be estimated indirectly. Our impressions of its frequency come from a variety of sources, none of which are comparable groups. These range from local surveys, army inductee examinations, hospital admissions, to sickness surveys of special groups. Dublin and Marks,1 in summarizing all available statistics, in 1946, state that the incidence appears to be 0.5% for all ages for the entire country, or more than 500,000 persons excluding those who have recovered. Representative examples of these statistics are shown in Table 1.1-6
Studies of the incidence of asthma in children and young people are even more meager than for adults. The sickness survey of Collins5 for 18 states reports rates