Abstract

Aim
PCRS has long promoted patient preference and patient inhaler technique ability as an example of precision medicine. In contrast, prescribing formularies are often driven by acquisition cost and, increasingly, environmental factors. We investigated whether there is a difference in asthma control between patients prescribed dry powder inhalers (DPIs) or pressurised metered dose inhalers (pMDIs).
Methods
Between 1st January 2022 and 30th April 2023, National Services for Health Improvement (NSHI) conducted audits of people with asthma in 447 practices across 111 CCGs / Health Boards / ICBs in the UK. Permission was obtained from participating practices to conduct research from anonymised aggregated data. Sequential patients aged 20 to 69 years with a clinical diagnosis of asthma, as identified by a READ code, were eligible for inclusion. Data collected included inhaler prescriptions, RCP3 score, courses of oral steroids and asthma hospital admissions.
Results
From the 116,841 asthma patients in the database, 96,074 were using either a single DPI or a single pMDI as a preventer medication. Patients on a pMDI were statistically more likely to have a lower RCP3 score than a DPI (p<0.001), use less oral steroids (p<0.001) and be associated with less hospital admissions (p=0.042). Details are shown in Figure 1.
The statistical significance observed is likely to have been influenced by the large sample size, as the percentage differences were numerically small between device types. These small differences are unlikely to result in clinically relevant differences between the devices.
Conclusions
Overall, the choice of device type does not appear to influence asthma control. It remains appropriate to choose the right device for the right patient.