IMPORTANCE OF CAREFUL DISEASE PHENOTYPING IN STUDIES ON DEVELOPMENT OF ASTHMA AND ALLERGIES

Background and Aims: The protection from childhood allergies and atopic sensitisation by farming environments has been shown in numerous studies. Reports on the ‘farm-effect’ on wheeze and asthma have been less consistent. We aimed to determine whether protection conferred by exposure to farming was different for various wheeze phenotypes and whether this protection was independent of atopic sensitisation. Methods: The GABRIEL Advanced Studies are cross-sectional multi-phase surveys on exposure to farming environments and its effect on asthma and allergic disease among 79,888 children at age 6 to 12. Detailed data on wheeze, exposure to farming environments, and total and specific immunoglobulin E were collected from a stratified random sample of 8,023 children. A further stratified random sample of 895 children was invited for lung function including bronchodilator response and exhaled nitric oxide measurements. We used adjusted weighted stratified regression analyses to assess effects of farming exposur...