Measuring adherence to inhaled control medication in patients with asthma: comparison among an asthma app, patient self-report and physician assessment

Abstract

We aimed to compare different measures of adherence to asthma control inhalers in clinical practice, namely through an app, patient self-report and physician assessment. This study is a secondary analysis of three prospective multicentre observational studies with patients (≥13 years old) with persistent asthma recruited from 61 primary and secondary care centres in Portugal. Patients were invited to use the InspirerMundi app and register their inhaled medication. Adherence was measured by the app as the number of doses taken divided by the number of doses scheduled each day and was assessed at two time points: 1-week (1wk) and 1-month (1mo). At baseline, patients and physicians independently assessed adherence to asthma control inhalers during the previous week using a Visual Analogue Scale (VAS 0-100). A total of 193 patients with asthma (72% female; Median [P25-P75] age 28[19-41] years old) were included in the analysis. Adherence measured by the app was lower (1wk: 31[0-71]%; 1mo: 18[0-48]%) than patient self-report (80[60-95]) and physician assessment (82[51-94]) (p<0.001). A negligible non-significant correlation was found between the app and subjective measurements (rho 0.118 to 0.156, p>0.05). There was a moderate correlation between patient self-report and physician assessment (rho=0.596, p<0.001). Adherence measured by the app was significantly lower than that reported by the patient or the physician, and lower than other objective methods reported in the literature. This low adherence may be due to the influence of adherence to the app itself and thus, this factor needs to be considereds in future analysis.