Epidemiology of asthma across the ages

Abstract

In the last three decades, the overall prevalence of asthma appears to be plateauing, although large geographical and socioeconomic variation is evident. Overall, asthma prevalence slightly decreased in most age groups, except for school-aged children. Of note, asthma mortality steadily decreased, potentially highlighting improved asthma management strategies. Several epidemiological studies indicate that a complex interplay between genetic, environmental and immunological factors predisposes individuals to asthma inception and persistence across different life stages. Established risk factors for preschool wheezing to asthma persistence comprise a combination of pre- and post-natal parameters including maternal history of asthma, prematurity, caesarian section, early- life respiratory infections, exposure to air pollution or tobacco smoke and allergic polysensitization. On the other hand, persistence into adulthood is mainly driven by disease severity, allergic multimorbidity, relevant comorbidities, severe respiratory infections and tobacco smoke exposure. It is evident that asthma prevention strategies do not fit a "one size fits all" concept and key environmental interventions should be tailored to different regions of the world. Undoubtedly, the heterogeneity of asthma as a disease is at least partly reflected in the reported epidemiological measures, and continuing, methodologically rigorous studies, will allow us to unravel some of the observed discrepancies.