Prevalence of Asthma and Asthma-like Symptoms: a Study in Five Provinces of Iran.

Background Asthma is a complex chronic inflammatory airway disease affecting millions of people worldwide. The prevalence of asthma attacks in most regions of the world, including the developing countries, increases due to urbanization, industrialization, and lifestyle. Materials and Methods The present study aimed at investigating the prevalence of asthma and asthma symptoms in five provinces of Iran using the stratified cluster sampling method and the European Community Respiratory Health Survey (ECRHS) questionnaire. Results A total of 4918 subjects were enrolled in the study. The prevalence of nocturnal cough was 27.4% (95% confidence interval (CI): 26%-28%); it was the most common asthma symptom followed by nocturnal shortness of breath (19.6%; 95%CI: 18-21%). For participants aged 20-44 years, the most prevalent symptoms were coughing attacks (37.7%), shortness of breath (26.5%), and nasal allergies (22.7%), respectively. Conclusion There was a significant association among gender, age, and nasal allergy. Relevant studies should be conducted to figure out the countrywide distribution and the real burden of the disease.