O5.2 Inhaler adherence

Bhattarai et al (2020) conducted a systematic review of 38 studies published from 2003 to 2019 that examined rates of medication adherence and reported on barriers and enablers to adherence. Rates of non-adherence ranged from 22% to 93%. The majority of studies identified the presence of depression and subjects’ concern about the harmful effects of the medicine as barriers to adherence (Bhattarai 2020).

A systematic review comprising predominantly retrospective database studies which measured prescription refill adherence with one to two year follow-up of patients with COPD found increased hospitalizations, mortality, poor quality of life and loss of productivity among non-adherent patients (van Boven 2014) [evidence level III-2].  Inhaler adherence and technique were found to be suboptimal in an observational study of use of an ICS/LABA combination inhaler fitted with an electronic audio recording device. Impaired lung function and cognition, as well as cough, predicted suboptimal adherence and technique (Sulaiman 2017).

A large retrospective study examined medication use data of patients with asthma and COPD from a digital health platform (smartphone application [mobile App] and electronic medication monitors). They compared adherence rates using a once daily controller regimen compared to twice daily. In 1791 patients with COPD, once daily was associated with higher median daily adherence than the twice daily regime 83.3% [IQR: 57.2 to 95.6] versus 64.7% [IQR: 32.8 to 88.9], p < .001). In COPD once daily regimen was also associated with an increased odds of achieving ≥80% adherence [1.73 (95% CI: 1.38-2.17, p < .001)]. Patients received electronic reminders via a mobile app if the medication was not taken, therefore inflating real life adherence rates. These data highlight the importance of identifying the regimen most likely to lead to improved adherence (De Keyser 2023) [evidence level III-I].

The National Asthma Council of Australia’s Australian Asthma Management Handbook contains further information about adherence: http://www.asthmahandbook.org.au/management/adherence.