Prevalence and risk factors of asthma among adolescents and their parents in Al-Ain (United Arab Emirates)

Background: Evidence indicates that the prevalence of asthma tends to increase in the developed world. However, little is known about current prevalence rates and risk factors of asthma in countries in transition, e.g. the United Arab Emirates (UAE). Objectives: We investigated the prevalence of asthma and its independent risk factors among adolescents and adults in Al-Ain, UAE. Methods: For a two-stage, randomly selected survey, 10,000 questionnaires were distributed to adolescents and their parents. Logistic regression was applied to assess asthma prevalence and independent associations with age, gender, education, nationality and family history. Results: In total, 6,543 subjects were included in the final analysis. Median age was 30 years (range: 8-93 years); 53% were male. The overall self-reported prevalence of asthma was 13%. Direct standardization with the UAE population as the reference yielded a prevalence of 12%. Logistic regression revealed family history and UAE nationality (about 50% of nationals were of Bedouin origin) as the main risk factors for asthma, and a significant (p = 0.001) interaction between gender and age: in the group aged 13-19 years, males had a significantly higher prevalence of asthma [17 and 14%; adjusted odds ratio (OR): 1.45; 95% confidence interval (CI): 1.10-1.90]; in the group aged >19 years, males had a significantly lower prevalence of asthma (11 and 13%; adjusted OR: 0.77; 95% CI: 0.60-0.95) than females. Conclusions: The prevalence of asthma is comparable to findings of earlier studies. The higher prevalence in adolescent males compared to females may possibly be due to sex-specific lifestyle factors. Strong predictors of asthma such as family history and UAE nationality may indicate modernization and possible genetic susceptibility, warranting further studies in this population.