Nonadherence in the era of severe asthma biologics and thermoplasty

Non-adherence to inhaled preventers impairs asthma control. Electronic monitoring devices (EMD) can objectively measure adherence. Their use has not been reported in difficult asthma patients potentially suitable for novel therapies, i.e. biologics and bronchial thermoplasty. Consecutive patients with difficult asthma were assessed for eligibility for novel therapies. Medication adherence, defined as taking 75% or more of prescribed doses, was assessed by EMD and compared to standardised clinician assessment over an eight week period. Among 69 difficult asthma patients, adherence could not be analysed in 13, due to device incompatibility or malfunction. Non-adherence was confirmed in 20/45 (44.4%). Clinical assessment of non-adherence was insensitive (physician 15%, nurse 28%). Serum eosinophils were higher in non-adherent patients. Including 11 patients with possible non-adherence (device refused or not returned), increased the non-adherence rate to 31/56 (55%). Severe asthma criteria were fulfilled by 59/69 patients. Forty-seven were eligible for novel therapies, with confirmed non-adherence in 16/32 (50%) with EMD data; including seven patients with possible non-adherence increased the non-adherence rate to 23/39 (59%). At least half the patients eligible for novel therapies were non-adherent to preventers. Non-adherence was often undetectable by clinical assessments. Preventer adherence must be confirmed objectively before employing novel severe asthma therapies.