Background and Importance The prevalence of asthma and scale of sub-optimal inhaled corticosteroid (ICS) use, demands efficient detection of non-adherence. The easy to administer Test of Adherence to Inhalers¹ (TAI) questionnaire asks patients to rate their agreement with 10-items, and the subsequent score classifies adherence as good, intermediate or poor. A more objective, though expensive tool, is the electronic monitor (eMonitor) that when attached to the inhaler, records the date/time of each actuation. If the person receives >75% of doses, this is good adherence. The biomarker Fractionated expired Nitric Oxide (FeNO) decreases following sustained ICS use. Thus, if eMonitor ICS adherence is good and there is a significant decrease in FeNO (>42% from baseline), pre-eMonitor adherence is unlikely. This is a positive FeNO suppression test² (FST). If there is no significant change in FeNO, this is a negative FST.

Aim and Objectives This study aimed to assess if the TAI could accurately detect non-adherence to an ICS in a cohort of people with difficult-to-control asthma.

Material and Methods Patients attending a hospital pharmacist asthma clinic completed the TAI, had FeNO measured and received an eMonitor. Follow-up was 6 weeks later.

Results Data for 88 patients were included, of whom 76 (86%) had good ICS adherence according to the eMonitor. 35 people had a positive FST; 12 (34%) had a TAI adherence that was designated good, 19/35 (54%) intermediate and 4 (11%) poor. In the negative FST group, 15/41 (37%) had a TAI adherence classification of good, 21 (51%) intermediate and 5 (12%) poor.

Conclusion and Relevance In this cohort, a third of patients with eMonitoring/biomarker evidence to suggest suboptimal ICS adherence (positive FST) completed a TAI that over-estimated ICS use. Conversely, in the FST negative patients (likely to have been adherent prior to eMonitor initiation), almost two-thirds of patients identified themselves on TAI as having suboptimal adherence. This suggests that the TAI may not accurately predict adherence or potentially, that using the eMonitor in itself encourages better adherence in the short-term.

References and/or Acknowledgements 1. Plaza V, et al. Test of Adherence to Inhalers Arch Bronchoneumol 2017;53:360–1.

2. Heaney LG, et al. Remotely Monitored Therapy and Nitric Oxide Suppression Identifies Non-Adherence in Severe Asthma. AJRCCM 2019;199(4):454–464.

Conflict of Interest No conflict of interest.