Background: The prevalence of asthma not only varies between countries but also between different regions within the same country. In the Middle East, asthma prevalence is reported to be lower than in developed countries.
Objective: This study was carried out to record the prevalence of bronchial asthma among adults in Qatar country and to detect the most common risk factors for the development of asthma.
Subject and methods: This study was conducted on 3752 subjects in Qatar in the period from January 2004 to June 2007. All subjects were subjected to detailed history taking, thorough physical examination, and ventilatory function tests. Serum IgE total and specific for the inhalants and food allergens were done in all asthmatic cases.
Results: Prevalence of current asthma was 7.65%. It was more common in females (51.5%), in industrial areas (59.1%), in those with positive family history of atopy (65.8%) and in low and moderate socioeconomic conditions (80%). It was independent of active smoking habits (26.1%).
Asthma was more associated with allergic rhinoconjunctivitis (53.7%) than with atopic dermatitis (17.1%). Air conditions, carpets, pets and smoking at home were all risk factors for the development of asthma. Total IgE was significantly higher among females. Allergy to both inhalants and food allergens were more common (58.9%) than to inhalants alone (25.1%) or foods alone (6.6%). Also, allergies to inhalant allergens (25.1%) were more common than to foods allergens (6.6%).
Conclusion: Asthma prevalence in Qatar was moderate in comparison to other gulf countries. The westernization in Qatar society and continuing extensive development in various sectors of the society resulted in increased prevalence of asthma in this country.

Key Words: Asthma; Prevalence; ECRHS; Risk factors; Qatar.