The measurement of adherence to inhaled corticosteroids in asthma using electronic monitoring devices: A systematic review and meta-analysis (Preprint)

BACKGROUND Electronic monitoring devices (EMDs) are increasingly considered the gold standard for quantifying inhaled corticosteroid (ICS) adherence in asthma. They are likely to play an important role in the future digitisation of self-management. However, there is a risk that early adoption without clarity of purpose could limit their utility. OBJECTIVE This review sought to ascertain an estimate of EMD-measured ICS adherence among people with asthma and understand the factors involved in their use. METHODS Searches were conducted in 2017 with updates in 2021 and 2023 across databases including Cochrane CENTRAL, MEDLINE, EMBASE, Web of Science, PsychINFO and IEEE Xplore. Studies were included if they used EMDs in adults with asthma and were randomised controlled trials (RCTs) or cohort studies. Summary data were extracted to inform narrative review and meta-analysis. The primary outcome was to derive a population estimate of ICS adherence. The study protocol is registered on the Prospero database (CRD42017057708). RESULTS Seventy-two RCTs and cohort studies were identified. RCT control groups were pooled with cohort studies for meta-analysis of the primary endpoint. Mean daily ICS adherence was 63.7% (95% Confidence Interval 59.2–68.2%, I2=98.9%). There was significant heterogeneity in device characteristics, study design, sample populations, definitions of adherence and use/choice of clinical outcome measures. CONCLUSIONS The findings suggest studies likely overestimate adherence compared to the general asthma population, even when objectively monitored. Minimum agreed standards for EMD outputs, accuracy, and agreed clinical outcome measures which are sensitive to digital interventions may be required for future research and clinical practice. CLINICALTRIAL N/A