Introduction: While mild asthma is generally better controlled than more severe disease, patients with mild asthma may experience severe exacerbations. Definite differences between countries in terms of asthma severity and control were described previously. Since SYGMA was a global study, this sub-analysis was conducted in geographic region to investigate potential regional specificities.
Methods: The SYGMA2 trial is double-blind multicenter study involving patients ≥12 years of age with mild asthma (n = 4176), eligible for regular treatment with inhaled corticosteroid (ICS). We conducted an open-label descriptive subanalysis of the baseline characteristics of the Russian population (n = 579) comparing to rest of participants of SYGMA2 trial from other 24 countries. The subanalysis is solely descriptive and will be used for hypothesis generation.
Results: The Russian population of patients with mild asthma hardly differs from the population in other countries in terms of baseline demographic and anthropometric characteristics, smoking status, and duration of asthma. At the study entry few patients from Russia received maintenance therapy with ICS and had symptom control, but the majority was uncontrolled on short-acting bronchodilators, thus the uncontrolled/controlled ratio was 52%/48% vs 45%/55% in other countries. More patients with mild asthma in the Russian group had faced at least one severe exacerbation in the previous year (30.1% vs 20.7%).
Conclusions: The subanalysis revealed a delayed prescription of controller (ICS) therapy and overuse of short-acting bronchodilators in the Russian population with mild asthma. These factors can lead to insufficient symptom control and higher risk of severe exacerbation in the Russian population with mild asthma.
Keywords: Epidemiology; mild asthma; morbidity and mortality; pharmacotherapy; therapy; treatment.