The effects of climate change on population health have considerably increased as the planet warms and is thus subjected to more heat waves, extreme weather events and food insecurity. Paradoxically, healthcare systems are major contributors to carbon emissions.

Within the field of respirology, choice of inhaler is a low-hanging fruit to address this issue. Metered dose inhalers (MDI) contain potent greenhouse gases and have been shown to have a significantly larger carbon footprint than dry powder inhalers (DPI).

The goal of the study is to assess asthma patients' willingness to change inhalers for environmental reasons as well as prescribers' willingness to prescribe a different inhaler for environmental reasons at the patient's request. The study will also be assessing patient awareness of the climate impact of inhalers and the importance that they attribute to this issue as well as other issues (cost and ease of use).

The effects of climate change on population health have considerably increased as the planet warms and is thus subjected to more heat waves, extreme weather events and food insecurity. Paradoxically, healthcare systems are major contributors to carbon emissions.

Within the field of respirology, choice of inhaler is a low-hanging fruit to address this issue. Metered dose inhalers (MDI) contain potent greenhouse gases and have been shown to have a significantly larger carbon footprint than dry powder inhalers (DPI).

Studies from the United Kingdom have revealed that although patient awareness of the discrepancy in climate impact of inhalers is low, their willingness to change inhalers after being educated on the subject is high.

An example of inhaler change is to use the Bricanyl Turbuhaler (terbutaline) instead of Ventolin (salbutamol) as a rescue medication in asthma. They are both short-acting bronchodilators (SABA) and have similar pharmacodynamics. However, use of Bricanyl for one year produces 7,183 kgCO2e or the equivalent of 59.9km by car, whereas use of Ventolin for one year produces 411,720 kgCO2e, the equivalent of 3,431 km by car.

The goal of the study is to assess asthma patients' willingness to change inhalers for environmental reasons as well as prescribers' willingness to prescribe a different inhaler for environmental reasons at the patient's request. The study will also be assessing patient awareness of the climate impact of inhalers and the importance that they attribute to this issue as well as other issues (cost and ease of use).

Inclusion Criteria:

• 18 years of age or older
• Followed in the asthma clinic at the Montreal Chest Institute or the Montreal General Hospital.
• Confirmed diagnosis of asthma presenting for a follow up visit for their asthma (defined as positive methacholine challenge test or confirmed reversibility of lung function 12% increase FEV1 (forced expiratory volume) or 200ml absolute value increase post bronchodilator).
• On an inhaled steroid for the treatment of asthma for maintenance as well as Ventolin MDI as a rescue inhaler.
• Stable asthma -not currently being evaluated for an acute asthma exacerbation and no Emergency Room visits for asthma within the last 30 days.
• Adequate lung function with a FEV1 of at least 50% and, where available, a peak inspiratory flow (PIF) of under 60L/m for use of a DPI and MDI.