Geoclimatic influence on the prevalence of asthma in adolescents: a multilevel analysis

Asthma is a chronic inflammatory disease of the airways presenting high global prevalence. Geoclimatic characteristics, especially relative air humidity, play an important role in its epidemiological profile, despite being still understudied. This study aims to evaluate the influence of individual and environmental geoclimatic factors on the prevalence of asthma in adolescents. A school-based epidemiological survey was carried out in 4569 adolescents (14 to 19 years). Regression models were applied to assess the association between asthma and factors related to the individual level [biological (sex, and age), family (history of asthma in parents, smoking history among parents and maternal level of schooling), behaviours (physical activity level and smoking cigarettes), socioeconomic (water at home and place of residence)]; further a multilevel model considering the socioeconomic and geoclimatic environmental characteristics of the place of residence was applied. The percentage of adolescents who had active asthma was 26.4% (22.9% dry climate vs. 27.9% humid climate). A higher risk of asthma was observed among females, (OR = 1.7, 95%CI = 1.5-2.1), individuals with history of asthma in parents (OR = 1.9, 95%CI = 1.5-2.5), smoking history among parents (mother, OR = 1.4, 95%CI = 1.4-2.0, father, OR = 1.5, 95%CI = 1.2-2.0 and, both, OR = 2.0,95%CI = 1.2-3.3) and, in adolescents who smoke cigarettes more than three days a month (OR = 1.9, 95%CI = 1.2-2.9). The likelihood of reporting asthma is significantly lower in the dry climate region (OR = 0.6, 95%CI = 0.4-0.9). These results will contribute to greater knowledge about asthma and its individual conditions living in dry climate conditions.