Supporting medication adherence in difficult-to-control asthma using electronic monitoring
Published online: April 1 2021
Poor adherence to inhaled corticosteroids (ICS) is common and is associated with poorer asthma outcomes and potentially inappropriate treatment escalation. Approximately 65% of people with difficult-to-control asthma who have a level of nitric oxide in their exhaled breath (FeNO) >45 pbb are non-adherent to ICS and can be identified using a 7-day FeNO suppression test. This involves prescribing additional ICS, with inhaler use measured over 7 days by an Inhaler Compliance Assessment (INCA) device, which records both the time the medication is taken and the quality of inhalation technique. This test also requires home FeNO measurements by the patient. A fall in the FeNO measurement of >42% indicates the patient is responsive to ICS (a FeNO suppressor) and identifies prior non-adherence. The 7-day test is problematic in a busy tertiary asthma clinic due to the cost and limited supply of FeNO meters for people to take home, the requirement to add another ICS inhaler to a patient’s treatment plan, and the inconvenience for people travelling long distances twice in a 7-day period. It is also not known whether this approach alters adherence behavior or has an effect on clinical outcomes.
In a recent article published in The Journal of Allergy and Clinical Immunology: In Practice, Boddy and colleagues report the findings from a clinical service evaluation. A simplified nurse-led 28-day FeNO suppression test was used where ICS/long-acting β-agonist (LABA) treatment was monitored using an INCA device, with measurements of FeNO, asthma control, lung function and blood eosinophils made in clinic at baseline and then again 28 days later. Patients identified as FeNO suppressors, or those found to have adherence of <80% to the prescribed dose, were offered further monitoring. At each visit, a specialist nurse provided education, checked inhaler technique, and gave feedback about the previous month’s results using the graphs produced by the INCA. The evaluation aimed to examine the effectiveness of the 28-day test compared with the 7-day FeNO suppression test. It also examined the clinical outcomes of people identified as FeNO suppressors or non-suppressors by the 7-day or 28-day test.
91% of patients offered the 28-day test accepted and completed a minimum of 28 days of monitoring. Results show that 66.6% of patients were identified as FeNO suppressors, similar to the results reported previously for the 7-day test. There were also significant improvements in forced expiratory volume in one second, asthma control scores, and blood eosinophils. Taking both 7-day and 28-day FeNO suppression tests together, only 35.5% of the FeNO suppressors progressed to biological therapy, compared with 72.7% of the FeNO non-suppressors. Once adherence had improved, FeNO suppressors taking maintenance prednisolone, who did not receive biological therapy, reduced the median baseline dose from 10 to 3 mg, with further reductions limited by adrenal suppression. In summary, the 28-day FeNO suppression test with clinic measurement of biomarkers gives similar results to the 7-day test and is acceptable to the majority of people with difficult-to-control asthma. Identification of prior medication non-adherence through INCA monitoring coupled with clinical support potentially improves patient adherence and asthma control longer term, preventing unnecessary progression to biological therapy.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.