At the Bennett Institute we regularly collaborate on projects, both small and large, with users who get in touch. For development of this measure we would like to thank the NHS England Sustainable Unit and Centre for Sustainable Healthcare for their input on our work to support the NHS Long Term Plan. Another one of our collaborators on this work is Nicola Read, a respiratory doctor who is currently one of the National Medical Director’s Clinical Fellows. Below we set our new measure on inhalers and the environment and Nicola explains its importance for all inhaler prescribers.

The NHS Long Term Plan (LTP) pledges to build a more sustainable NHS and reduce the negative effect the NHS has on the environment. It identified inhalers as an area where changes in practice could deliver a reduction in the NHS carbon footprint. Inhalers are commonly prescribed to people with respiratory conditions, including asthma and chronic obstructive pulmonary disease (COPD) and there were over 50 million prescriptions for them across England in the last 12 months. Broadly speaking, most inhalers are of two main types: metered dose inhalers (MDI), which use hydrofluorocarbons (HFC) as a propellant, and dry powder inhalers (DPI), which use no propellant but do need people to have a certain inspiratory flow rate in their lungs for effective delivery of the medicine. HFCs are powerful greenhouse gases that contribute to global warming. The NHS aims to use more dry powdered inhalers, where clinically appropriate.

We have created a measure which shows the number of of MDIs (excluding salbutamol) as the proportion of all inhaler prescriptions that are MDI or DPI (again excluding salbutamol). We exclude all salbutamol inhalers from this measure, for reasons described below. The measure examines every practice, CCG , STP and region in England, to support areas to review their use of MDIs and switch to DPIs where appropriate, in order to deliver the commitments in the LTP.

However, it may not always be appropriate to switch to DPI. There are several reasons that are important when deciding which type of inhaler to prescribe:

  • Available alternatives — Some inhalers are only available in an MDI form.
  • Clinical suitability — Some patients, such as those with low inspiratory flow rate, may not be able to use a DPI effectively and it is not clinically appropriate to switch.
  • Specific HFC in an MDI — Depending on the specific HFC that is used, some MDIs having greater global warming potential (GWP) compared to others. If the medication has no DPI alternative, there may be an MDI alternative with a lower GWP.
  • Local formulary choice — Most areas have a local formulary and make recommendations based on the evidence, cost and local services available

Why have we excluded salbutamol from the measure?

Salbutamol is the most commonly prescribed inhaler and is usually prescribed as an MDI. It is generally known as a “blue inhaler” or “reliever” and used in an acute asthma attacks. We have excluded it for two main reasons: a) about 60% of salbutamol inhalers are prescribed generically, so we can’t tell from the prescribing data which manufacturer’s MDI, and therefore the GWP, has been supplied b) further clinical review may be necessary to ensure a DPI is suitable even in the event of an asthma attack. We have some more measures coming soon on salbutamol, but please get in touch if you have any ideas or strategies to manage this particular issue.

Other resources to support shared decision making

Clinicians have a duty to undertake shared decision making with patients, which should include discussing the environmental impact of treatment choices. There are a range of resources available to help clnicand and patients to support a shared and informed decision around inhalers. Some examples we have found include;

Future developments

At the Bennett Institute we are always keen to hear from people who would like to collaborate with us on projects and we pride ourselves on developing our tools swiftly and iterating them based on the needs of our users. Please get in touch if you have any suggestions or have thoughts on this measure via