The characteristics of bronchial asthma among a young adult population.

A total of 107, 636 subjects of both sexes who were drafted into the Israeli Defense Forces during 1986 to 1988 were analyzed for the presence of asthma based on questionnaire responses and the results of pulmonary function tests. Most patients (79%) had either mild or inactive disease. Lifetime prevalence increased by 21.7% from 5.3% in 1986 to 6.5% in 1988. The results of a follow-up carried out over 5 to 7 years showed no major change in severity in most patients. The incidence rate remained stable throughout 1987 to 1989 (275, 245, and 243 per 100,000, respectively), without there being any major change in the severity of the asthma during the subsequent 3 to 5 years. It was also revealed that the more physically demanding jobs were associated with a higher prevalence of job transfer. The results of this study suggest that the factors causally associated with asthma are relatively more active during early childhood.