Wheeze and asthma prevalence and related health-service use in white and south Asian pre-school children in the United Kingdom.

Background: Epidemiological data for south Asian children in the UK are contradictory, showing a lower prevalence of wheeze, but a higher rate of medical consultations and admissions for asthma compared to white children. These studies have not distinguished different asthma phenotypes or controlled for varying environmental exposures. Objective: To compare the prevalence of wheeze and related health-service use in south Asian and white preschool children in the UK, taking into account wheeze phenotype (viral and multiple wheeze) and environmental exposures. Methods: A postal questionnaire was completed by parents of a population-based sample of 4366 white and 1714 south Asian children aged 1 to 4 years in Leicestershire, UK. Children were classified as having viral wheeze or multiple trigger wheeze. Results: Prevalence of current wheeze was 35.6% in white and 25.5% in south Asian one year-olds (p<0.001), and 21.9% and 20.9%, respectively in children aged 2 to 4 years. Odds ratios (95% CI) for multiple wheeze and for viral wheeze, comparing south Asian with white children, were 2.21 (1.19-4.09) and 1.43 (0.77-2.65) in 2 to 4 year-olds after controlling for socioeconomic conditions, environmental exposures and family history. In one year-olds the respective ORs for multiple and viral wheeze were 0.66 (0.47-0.92) and 0.81 (0.64-1.03). Reported GP consultation rates for wheeze and hospital admissions were greater in south Asian children aged 2 to 4 years, even after adjustment for severity, but use of inhaled corticosteroids was lower. Conclusions: South Asian 2 to 4 year-olds are more likely than white children to have multiple wheeze (a condition with many features of chronic atopic asthma), after taking into account ethnic differences in exposure to some environmental agents. Undertreatment with inhaled corticosteroids might partly explain their greater use of health services.