Prevalence of childhood asthma, allergic rhinitis and eczema in Urumqi and Beijing.

Abstract

To assess the prevalence of asthma and other allergies in children in Urumqi and Beijing, compared with that in Hong Kong. A total of 7754 primary school students were randomly selected to participate in the study. Data were collected in 1995-96 using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol for 6- and 7-year-olds. The study design and data quality assurance in all aspects followed the protocol, including the double entry of data. The questionnaire response rate was high (98.9%). Beijing children reported significantly more asthma than those living in Urumqi in three categories: wheezing or whistling in the chest in the past year (6.0%, 95% confidence interval (CI): 5.1-6.9% vs 2.9%, 2.3-3.5%, P < 0.001), sleeping disturbed due to wheezing (1.3%, 0.9-1.7% vs 0.6%, 0.3-0.9%, P < 0. 03) and having experienced asthma ever (10.7%, 9.6-11.8% vs 7.6%, 6. 6-8.6%, P < 0.001). The prevalence of allergic rhinitis (30.0% vs 31. 1% estimated as 12-month nasal symptoms in Beijing and Urumqi, respectively) and eczema (2.8% vs 2.0% recorded as 12-month itchy rash) in the two cities were not significantly different. A similar study was also performed in Hong Kong in 1995 using the same ISAAC protocol. The children in Urumqi and Beijing had fewer (P < 0.05) allergic symptoms compared to those living in Hong Kong (n = 3618). The 12-month prevalence of wheezing, nasal symptoms and itchy rash found in Hong Kong were 9.2% (95% CI: 8.2-10.2%), 35.1% (33.5-36.7%) and 4.2% (3.5-4.9%), respectively. : Urumqi, Beijing and Hong Kong represent communities at different stages of westernization and the results from these three cities reflect a worldwide trend for an increasing prevalence of allergies along with westernization. These three cities could assist in identifying risk factors involved in the increase in asthma, allergic rhinitis and eczema.