Abstract
Asthma admissions among children under 15 years of age have increased nearly three-fold over the period 1959-73. The possible reasons for this increase have been examined using available data supplemented by the results of a special study of hospital disease indexes and case notes. Changes in diagnostic coding and trends in diagnostic fashion do not appear to be important. Part of the increase may be due to an increase in readmission rates. Changes in admission criteria resulting from changes in therapy, organisation of care, and illness behaviour have been considered. However, on present evidence an increase in morbidity cannot be excluded, and this could be investigated by repeat prevalence surveys of schoolchildren. If morbidity remains unchanged, admission policies for children with asthma should be reviewed.