An interventional study of WAN Inhaler Guidelines plus carbon footprint information and WAN Inhaler guidelines only in Asthma, sponsored by Portsmouth Hospitals NHS Trust. Completed at 1 site in United Kingdom. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-17.
Sponsored by Portsmouth Hospitals NHS Trust · Not applicable, Interventional, and Other
Climate change is a huge and present threat, with the devastating effects being increasingly seen in everyday life. The NHS contributes substantially to the UKs carbon footprint with an estimated 23 million tonnes gCO2Eq per year, 3% of which comes from pMDIs. There are a number of alternative inhalers, such as DPIs, which do not use propellant and therefore have a significantly lower carbon footprint. There is a call to move towards greener inhalers as part of the NHS long term plan for sustainability, to reduce the carbon footprint and therefore the environmental impact and help protect the health of our patients today and in the future.
When recommending an inhaler, a number of factors are usually considered including the ability of the patient to use the device and its cost. Up until now the environmental impact of each inhaler is not routinely available and therefore is not normally considered in prescription choice. Given the increasing evidence supporting the sizeable impact that pMDIs are having on global warming, there needs to be a shift in practice where the climate impact forms part of the decision-making process.
This study is looking to explore prescribing behaviours surrounding inhaler selection and in particular whether knowledge of the carbon footprint of inhalers has any sway on prescribing preference. By better understanding the decision-making process, this will allow the production of more comprehensive asthma management guidelines and potentially facilitate a drive to greener inhaler prescribing practices.
Inhalers are some of the most commonly prescribed medicines in the UK and can be expensive. They form the mainstay of treatment for asthma and COPD. They comprise either a pressurised metred dose inhaler (pMDI) or a dry powder inhaler (DPI). Despite global legislation some years ago that removed chlorofluorocarbons (CFCs) from inhalers (Montreal Protocol) due to their harmful effect on the ozone layer; there remains a large difference in the carbon footprint between pMDIs and DPIs. pMDIs have a higher carbon footprint than DPIs and contribute substantially to global warming. The effects of this are to be seen in everyday life and it is the responsibility of all individuals to 'reduce their carbon footprint'.
The environmental impact of inhaler use also comes from plastic waste from discarded inhalers. Over 50 million inhalers are prescribed in the UK each year1, and most of these will end up in landfill sites where they take centuries to biodegrade. There are an increasing number of schemes to recycle inhalers and local pharmacies will often provide these facilities, but this is not routinely advertised to patients.
Current guidelines recommend that where either a pMDI or DPI will be equally as good for the patient then the environmental impact of the inhaler should be considered. TheNational Institute for Health and Care Excellence (NICE) provides national guidance and advice to improve health and social care. Their guidance includes an algorithm to choose the best inhaler for a patient. Whilst this is helpful on an individual patient basis, there is currently no legislation that mandates the use of DPIs in preference to pMDIs.
The study hypothesises that if Health Care Professionals (HCPs) are provided with the information on the carbon footprint of each inhaler, this may influence the type of inhaler they recommend, i.e., with all things being equal they may show a preference for low carbon DPIs over high carbon pMDIs because of concerns over global warming.
A simple online study has been designed to test whether HCPs, if given information regarding the environmental impact of inhalers, as part of an asthma treatment guideline, are more or less likely to recommend a low carbon inhaler. By better understanding how the inclusion of carbon data influences inhaler prescription choice, we will be able to clarify whether the inclusion of carbon data in asthma treatment guidelines is likely to be beneficial in facilitating a drive to greener inhaler prescribing practices.
Exclusion Criteria:
Participants receive the current standard Wessex Asthma Network inhaler guidelines with no information regarding the carbon footprint of individual inhalers
Other: WAN Inhaler guidelines only
Participants receive the Wessex Asthma Network inhaler guidelines plus information containing the carbon footprint for individual inhalers.
Other: WAN Inhaler Guidelines plus carbon footprint information
Wessex Asthma Network inhaler guidelines plus the carbon footprint infromation for individual inhalers.
current standard Wessex Asthma Network inhaler guidelines with no information regarding the carbon footprint of individual inhalers
Health Care Practitioner Preference
The number and proportion of HCPs preferring high or low carbon inhalers between carbon-containing and non-carbon-containing groups, for each case separately and across all cases in total.
Time frame: At completion of the online questionnaire (approximately 10 minutes)
Rank Order of Preference
The rank order of preference of carbon footprint, patient's ability to use the device, cost of device, dosing schedule and clinical evidence for the device in carbon-containing and non-carbon-containing groups. Sensitivity analyses will assess the influence of HCP role, care setting, prescribing status, HCP experience, respiratory specialist status, age, use of WAN guidelines and case scenario.
Time frame: At completion of the online questionnaire (approximately 10 minutes)
Inhaler Recycling Recommendation
The proportion of HCPs that recommend inhaler recycling to their patients.
Time frame: At completion of the online questionnaire (approximately 10 minutes)
Inhaler Recycling Facilities
The proportion of HCPs that have inhaler recycling facilities available in their clinical setting.
Time frame: At completion of the online questionnaire (approximately 10 minutes)
Use of Wessex Asthma Network Guidelines
The proportion of HCPs that confirm the use of Wessex Asthma Network guidelines in their clinical practice.
Time frame: At completion of the online questionnaire (approximately 10 minutes)
Plan to share: No
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Portsmouth Hospitals NHS Trust