Assessing adherence to inhaled medication in asthma: impact of once-daily versus twice-daily dosing frequency. The ATUAD study
Luis Pérez de Llano, Abel Pallares Sanmartin, Francisco Javier González-Barcala, et al.
J Asthma 2018; published online 20 February 2018
Adherence to asthma treatment is reported to be around 50%, even in patients with difficult-to-manage asthma. This study by Luis Pérez de Llano (Hospital Lucus Augusti, Lugo, Spain) and colleagues recruited adults with asthma from six outpatient asthma clinics in tertiary hospitals in Spain. A total of 180 patients attended the two study visits, six months apart. Eighty-six followed a once-daily inhaled medication regimen, while 94 followed the more common twice-daily strategy. Adherence, measured by the Test of Adherence to Inhalers (TAI), increased from visit one to visit two in both groups but these differences were insignificant. However, at the second visit 29.8% of patients on once-daily treatment scored <50 points on the TAI (indicating non-adherence), compared with 46.9% in the twice-daily group (p=0.01). This was supported by the electronic prescription refill rate, which was <80% (again, indicating non-adherence) in 22.6% of once-daily patients and 37.5% of the twice-daily group. Interestingly, there were no differences in clinical outcomes between adherent and non-adherent groups. The authors caution that although once-daily treatment may support adherence, missing a single dose means missing a whole day of treatment, which could lead to worse clinical outcomes. Nonetheless, this study seems to indicate that once-daily dosing may lead to increased adherence to asthma maintenance treatment.