Sustainable asthma inhalers: who is offered the option to change, who declines and who successfully switches?

BACKGROUND: The healthcare community recognises the need for lower emission inhaler options; however, in the UK, most inhalers prescribed are pressurised metered dose inhalers (pMDIs) despite dry powder inhalers (DPIs) having a markedly lower carbon footprint as they do not contain propellants. For this reason, UK clinicians have been encouraged to offer switches from pMDIs to DPIs where feasible. METHODS: Using data from the Asthma+Lung UK's 'Life with a Lung Condition' 2023 online survey, demographic, economic and clinical factors were analysed to determine who had and had not been offered a switch; whose switch had been successful and why some respondents chose not to switch. RESULTS: 9960 people with asthma responded (77.9% female; age 59.9±13.0) and 7059 (87.7%) were pMDI users. The 3753 (53.2%) who were offered a pMDI to DPI switch had a greater awareness of lower-emission inhaler options (72% vs 53.2%*), uncontrolled asthma (61% vs 54.1%*), and had required unscheduled healthcare (27.4% vs 21.2%*) or >2 courses oral corticosteroids (27.6% vs 21.6%*) in the last year (all *p<0.001). 432 (11.5%) opted not to change inhaler when offered. 3321 (88.5%) accepted the switch and it was successful in 2126 (64%). DISCUSSION: In a large UK survey of people with asthma, over half of those on pMDIs had been offered a switch. It was successful in most who attempted it but unsuccessful switches were associated with subjective and objective markers of poor disease control. Some patients decline the switch because they like their pMDI, but some have ongoing concerns about the efficacy and safety of a DPI and is most feasible when integrated into routine reviews for patients with stable disease, alongside ongoing efforts to optimise asthma outcomes.