The role of environmental impact in healthcare providers' choices of inhalers for treatment of asthma and COPD: a discrete choice experiment.

Background: Pressurised metered-dose inhalers (pMDIs), often prescribed for the treatment of COPD and asthma have a high global warming potential (GWP) compared to dry powder inhalers (DPIs) and soft-mist inhalers. Despite calls to switch from high to DPIs or soft-mist inhalers, prescriptions of pMDIs have increased in recent years. Understanding healthcare providers' preferences can help develop strategies to promote prescribing low GWP inhalers. This study aimed to determine healthcare providers' preferences when prescribing inhalers for asthma and COPD, including its GWP (i.e. environmental impact).

Methods: A survey containing a discrete choice experiment was conducted. Primary care providers were repetitively asked to choose between scenarios of inhalers that differed in five attributes: multidose or unidose system (i.e. ease of use), reduction in number of exacerbations, side effects, out of pocket costs and GWP. A multinomial logit model was used to determine the relative importance of the attributes.

Results: A total of 76 healthcare providers (general practitioners (GPs), nurse specialists and nurse practitioners) completed the survey. On average, the attribute 'reduction in number of exacerbations' was most important in their choice for inhalers, followed by, 'side effects', 'GWP', 'out of pocket costs', and 'multidose or unidose system'. Healthcare providers were willing to accept a high GWP inhaler instead of a low GWP inhaler when the inhaler reduced the number of exacerbations and were willing to opt for low GWP inhaler with higher out of pocket costs instead of a high GWP inhaler with lower out of pocket costs.

Conclusions: Healthcare providers valued clinical factors (i.e. reduction in number of exacerbations and low side effects) as most important when choosing inhalers for their patients with COPD or asthma, however GWP was also an important driver of choice. Understanding these preferences can support strategies to support sustainable inhalers for COPD and asthma, contributing to climate change mitigation. For example by enhancing the provision of information regarding inhaler GWP, while ensuring that clinical effectiveness remains the primary focus.