Epidemiology of childhood asthma

There is considerable concern in several countries that the death-rate for asthma is rising among children. Hospital admission-rates have been rising steeply in England and Wales, as in other countries; the rise does not seem to be attributable to the admission of less severe cases. The possibility of increasing prevalence is difficult to assess because of the lack of a clear-cut definition of asthma and the consequent uncertainty as to whether children are now labelled as asthmatic who formerly would not have been. Repeat surveys using identical methodology are needed to provide reliable information. In 1973 a survey was conducted in South Wales among 12-year old children, and repeated in the same area in 1988. An increase has occurred in reported asthma, in relevant symptoms, and in exercise-induced bronchospasm. Data from Sweden, Finland, New Zealand and elsewhere suggest that the rise in asthma is a worldwide phenomenon, and is associated with some environmental factors in the developed countries. The cause of the increase is a matter of speculation.