Supplementary Material for: Decline in Asthma Prevalence and Severity in Israel over a 10-Year Period

Background: The prevalence of asthma has increased in western countries towards the end of the last century, but recently seems to have stabilized. Objective: To evaluate trends in the prevalence and severity of asthma that occurred in Israel over the past decade. Methods: The medical records of 17-year-old boys, eligible for national service, between 1999 and 2008 were reviewed. National annual hospitalization and death rates for asthma were extracted. Results: Three hundred thousand medical records were reviewed. During the study period, lifetime asthma prevalence decreased from 9.7 to 8.1% (p = 0.002). The point prevalence of moderate-to-severe and mild persistent asthma decreased significantly from 0.88 and 3.41% to 0.36 and 2.44%, respectively, during this period. The prevalence of intermittent asthma and asthma in clinical remission for more than 3 years did not change significantly. The annual hospitalization rate for asthma decreased from 13.0 to 7.5 per 10,000 population (p < 0.0001), whilst the annual death rate due to asthma decreased between 1999 and 2008 from 2.1 to 1.4 per 100,000 population (p = 0.003). Conclusions: The prevalence of asthma in Israeli teenage boys decreased significantly over the last decade. In addition, asthma hospitalization and asthma-related death rates in the total population also decreased.