Adolescents with asthma are usually insufficiently adherent to regular inhalation treatments, thus limiting their effectiveness. The aim of this study is to investigate the role of adherence to single-inhaler long-acting LABA/ICS dry-powder combination o.d. in affecting lung function, bronchial hyperreactivity, and health outcomes over a twelve-month survey of a group of non-smoking adolescents with mild to moderate asthma. Methods: Age, gender, BMI and atopy, forced expiratory volume in 1 s (FEV1), maximum mid-expiratory flow (MMEF), and maximum expiratory flow at 25% of lung filling (MEF25) were assessed via a Boolean selection process from the institutional database at recruitment, as well as after 6 and 12 months, together with the incidence of exacerbation, school days that were taken off, GP and specialist visits, and systemic steroid and/or antibiotic courses. Adherence was checked monthly via a direct telephone call. Statistics were calculated with an ANOVA trend analysis, assuming p < 0.05. Results: Two well-matched sample groups of 54 subjects each were obtained. The mean annual adherence to treatment ranged from 48.2% doses ± 10.9 sd to 79.3% doses ± 8.8 sd (p < 0.001), regardless of age and gender. Only adolescents that adhered to the o.d. ICS/LABA inhalation regimen progressively achieved complete control of all lung function parameters (FEV1: 0.001; MMEF: p < 0.002; MEF25 < 0.001; <0.001), minimized their bronchial hyperreactivity (p < 0.001), and optimized all health outcomes (p < 0.001—p < 0.002) over the survey duration. Discussion: A good adherence to treatment is essential for asthma management, particularly in young patients. Factors that are totally independent of the complexity of the therapeutic regimen adopted (namely, only a once-daily inhalation in the present survey) probably represent the major reasons limiting the adolescents’ adherence. Cultural, educational, behavioral, and psychological factors are frequently involved, are difficult to control, and can present barriers to adolescents’ asthma management. Further studies aiming to deeply understand and possibly remove the reasons for such adolescents’ attitudes are needed, in cooperation with actions oriented in this direction by families, educators, and health professionals.
Keywords: adherence to treatment; adolescents; asthma.