Investigating attitudes and insights into the global warming impact of inhalers
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Obstructive airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), affect over 800,000 people in New Zealand and are major contributors to morbidity and mortality.[[1]] Inhaled medication is the mainstay of treatment for most patients.[[2–4]] There are three main types of inhalers available: pressurised metered dose inhalers (pMDIs) use a propellant to aerosolise the medication; dry powder inhalers (DPIs) contain a compacted drug powder that is broken up by inspiratory pressure when inhaled; and soft mist inhalers (SMIs) convert a liquid form of the medication into a fine spray under an external pressure.[[5,6]]
Most medication classes are available in both pMDI and DPI preparations, and studies show that these have comparable efficacies in the management of asthma and COPD in both routine day-to-day use and in emergency settings.[[7–10]] SMIs may achieve more efficient drug delivery and greater symptom improvement in patients with COPD compared to pMDIs, but fewer medications are available in this form.[[11]]
Patient factors, such as ease of use and effectiveness, are the most important consideration when choosing which type of inhaler to use: for example DPIs may not be suitable for those who cannot generate an adequate inspiratory pressure such as young children or elderly patients.[[12]] However, DPIs are associated with lower rates of errors concerning inhaler technique than pMDIs.[[13]] Similarly, most patients quickly master the correct inhaler technique for SMIs.[[14]] Cost is another consideration: while DPIs tend to be more expensive than pMDIs, most are fully subsidised in New Zealand.[[15]] Beyond these considerations, clinicians’ prescribing appear to be mostly guided by familiarity, local protocols and availability, reflected by the considerable variation in the use of pMDIs and DPIs worldwide: 70% of inhalers prescribed in England are pMDIs, compared to only 10% in Scandinavian countries.[[16]] In New Zealand, there has been a decrease in the proportion of pMDIs from 75% of dispensed inhalers in 2017 to 66% in 2020.[[15]]
Another factor that should be considered when choosing the right inhaler is the environmental impact.[[17]] The healthcare sector in OECD countries is estimated to contribute 3–8% of the nation’s total greenhouse gas emissions, and inhaled therapy makes up a substantial proportion of this.[[18–20]] The propellants presently used in pMDIs are hydrofluorocarbons (HFCs), which are potent greenhouse gases.[[21]] They are currently responsible for 3.5% of the carbon footprint of the United Kingdom’s National Health Service. Overall, these propellants are estimated to contribute 0.03% of global greenhouse gas emissions.[[22,23]] The global warming potential of one 200-actuation pMDI canister is equivalent to driving 290 kilometres in a small car.[[23]] Although there are substantial differences in the global warming potential of different propellants and the quantity contained in different inhaler brands, all current pMDIs have a much greater carbon footprint than DPIs or SMIs.[[17]] DPIs and SMIs do not contain propellants and have an approximately 95% lower carbon footprint.[[24,25]]
A 2017 study performed in London found that 80% of patients and 68% of physicians believed that the carbon footprint of inhalers was important.[[26]] There is no research looking at the opinions of prescribers and patients regarding changing inhalers for environmental reasons in New Zealand. We investigated the factors that patients and practitioners consider when making decisions relating to inhalers.
Methods
A quantitative and qualitative study was performed. We invited patients and practitioners aged 18 years or over in Dunedin or Invercargill who use, prescribe or give advice on inhalers. Patients were recruited from medical centres, hospital outpatient waiting rooms, and inpatient wards. Practitioners were contacted by email and by phone. Additionally, QR codes linked to a digital version of our questionnaire were placed in waiting areas in medical centres and hospitals. Demographic information about age, gender, ethnicity, patients’ location, disease and highest level of education, and practitioners’ role and country of training was collected. Ethnicity and gender questions were based on the 2018 and 2023 New Zealand Census.[[27,28]] Separate questionnaires were created for patients and practitioners using Qualtrics[[XM]] (Seattle, WA, USA) software, using both open-ended and structured answers (see Appendix). Questionnaires were completed online or on paper and took 5 to 10 minutes to complete. A chart was used to identify the types of inhalers.[[29]] A brief explanation of the effects of HFC inhaler propellants on the environment was provided towards the end of these questionnaires.[[30]]
Analyses were performed using GraphPad Prism 9.4.1 (GraphPad Software Inc., California, USA). Data values are expressed as mean ± standard error of the mean (SEM). Data distributions were tested for normality using a D'Agostino-Pearson test. Normally distributed measures were compared using unpaired student’s t-Tests. Non-parametric measures were compared using a Mann–Whitney U test or one-way analysis of variance (ANOVA) on ranks followed by post hoc Dunn’s multiple comparisons tests. Categorical outcomes were compared using a Chi-squared test. Statistical significance was determined as a two-sided p-value <0.05.
Informed consent was given verbally or in writing. The study was approved by the University of Otago Ethics Committee.
Results
View Figures 1–3 and Table 1.
Fifty-three patients and 16 practitioners were included (Figure 1, Table 1).
Thirty-four (64%) patients were currently using a pMDI, 28 (53%) a DPI, and 8 (15%) an SMI. Seventeen (32%) were using multiple types of inhalers. There were no differences in types of inhalers between diseases. Most patients were “somewhat satisfied” or “satisfied” with their inhalers. There was little difference in satisfaction between those only using pMDIs (75%) versus DPIs (89%).
Factors influencing patients’ willingness to change inhaler type
The most important factor for patients changing an inhaler was symptom relief, with 47/53 (89%) of people rating this as “somewhat agree” or “strongly agree”. Most patients also considered ease of use 37/53 (70%), environmental impact 36/53(68%) and cost to the healthcare system 26/53 (49%) to be important, although symptom relief scored more highly than any of these (Figure 2).
Forty-four out of 53 (83%) of patients agreed or strongly agreed that global warming is an important issue and 35/53 (66%) considered the environmental impact of the healthcare that they receive. 26/53 (49%) of patients reported being aware that inhalers had some form of environmental impact.
Patients who consider the environmental impact of their healthcare were more likely to rank the environmental impact of inhalers as important than those who did not (p=0.040). There were no substantial or statistically significant differences between those concerned about global warming or aware of the environmental impact of inhalers, or between age, gender or disease. After information was provided on the environmental impact of inhalers, there was no appreciable difference in the willingness to consider the environment when choosing inhalers.
Factors influencing practitioners’ willingness to change inhaler type
All practitioners rated symptom relief and ease of use as having “some influence” or a “strong influence” in their decision of inhaler type. These were more important than both environmental impact and cost to the healthcare system (Figure 3).
Twelve out of 16 (75%) of practitioners believed global warming to be “very” or “extremely” important, but only 10 were aware of the difference in global warming potential between pMDIs and DPIs. After being given information about the environmental impact of the different types of inhalers, the number of practitioners who said that the environment would have either some influence or a strong influence on their prescribing increased from four (25%) to 12 (75%) (p=0.029). Practitioners’ concerns around DPIs included some patients not being able to use them due to their age or severity of disease, their ease of use, not wanting to change inhalers if patients had stable disease control on pMDIs, patient preference and a lack of familiarity with DPIs.
Discussion
We found that most patients and practitioners are willing to consider environmental impacts when choosing their inhalers once they had been made aware of the differences between inhaler types. Most patients expressed willingness to change their inhaler based on environmental considerations if their doctor recommended it.
As expected, the priorities for both patients and practitioners are ease of use and efficacy or symptom control. Most people who were unwilling to change their inhaler for environmental reasons indicated that they feared their disease would get out of control. However, DPIs have been shown to be as effective as pMDIs in controlling symptoms of both asthma and COPD, and improvements in quality of life and clinical outcomes have been observed when switching asthma and COPD patients from pMDIs to DPIs.[[7–10,31]] Furthermore, while the use of a short-acting beta-agonist pMDI with a spacer is currently the first-line intervention for acute severe bronchospasm, a review of 23 randomised trials found that the administration of short-acting beta-agonist through DPIs was as effective in treating acute severe asthma as pMDI therapy, both with and without a spacer.[[2–4,32]] Therefore, there may be scope for many patients to change to DPIs without compromising symptom relief and disease control. On the other hand, young children may not be suitable for DPI therapy due to the intricacies of their use and the lack of evidence in this age group.[[33]] All paediatricians in this study said that they prescribe pMDIs most frequently. Older children have been shown to use DPIs effectively and may be suitable for a trial of DPI therapy, but there are few studies of this.[[33]] Future reductions in the environmental impact of pMDI use in this age group could eventually be achieved through the use pMDI propellants with a lower global warming potential. These are currently being developed, but it will be several years before these become available.[[17,34]]
Most participants thought that global warming was an important issue, and two thirds considered the environmental impact of the healthcare they receive. However, only half of the participants were aware of the impact that inhalers have on the environment. Educating patients about this issue to increase awareness may influence future healthcare decisions to reduce global warming and environmental harm. However, we did not find that providing brief written information on the global warming potential of different inhalers made any immediate difference to patient attitudes to inhaler choices.
The wider environmental impact of inhaled treatment is less well understood. Although pMDIs have much greater overall global warming effects due to their hydrofluorocarbons propellants,[[7–10,24]] the full life cycle of DPIs may have greater impacts on fossil depletion, terrestrial acidification, freshwater and marine eutrophication and ecotoxicity, and the formation of photochemical oxidants due to the use of greater amounts of plastic and raw materials in their manufacture.[[24]] Future improvements in inhaler manufacture and reuse/recyclability of these inhalers may reduce these impacts.[[17]] However, none of these are as urgent as reducing the global warming potential of inhalers in the face of the current climate emergency. Another drawback is that many DPI inhaler devices are patented, making it more difficult to replace them with cheaper generic drugs, although most classes of drug now have several alternative preparations. As noted above, new propellants with a lower global warming potential may eventually make pMDIs an environmentally friendly and cost-effective choice.
Most hospital-based physicians and nurse specialists were aware of the difference in global warming potential between inhaler types, although providing written information did appear to increase the influence of environmental impacts of their inhaler choices. Ease of use and efficacy of the inhaler are the most important factors to consider when choosing inhalers. However, switching patients from pMDI- to DPI-based maintenance therapy reduces the annual inhaler carbon footprint by 55% without loss of asthma control.[[10]] Good disease control is important for environmental as well as clinical reasons: suboptimal disease control resulting in overuse of relieving medications may contribute to two thirds of greenhouse gas emissions from inhalers.[[35]]
To our knowledge, this is the first New Zealand study into environmental influences on inhaler prescribing and patient preferences regarding inhaler choices. Strengths include using both quantitative and qualitative techniques to gain a greater understanding of these factors. Interviewer bias was minimised by using standardised questionnaires, however, we did not validate the questionnaires and having multiple interviewers meant that it is possible that there were subtle differences in how participants were asked the questions. Social desirability bias may have resulted in a higher estimate of participants that consider the environment to be an issue compared to the actual population. Many patients were excluded for practical reasons (such as infection control or frailty), and we recruited only a small proportion of the practitioners that we approached. Other limitations of this study include an overrepresentation of inpatients, and the single-area setting (Southern), which led to a mostly older patient group with a higher proportion of NZ Europeans than the whole of New Zealand.[[36]] This is important because Māori and Pacific people experience a higher burden of respiratory disease. It would be informative to investigate these issues with different age and ethic patient groups and a larger sample of practitioners. We also need research on the efficacy of DPIs in young children and more data on their use in acute asthma exacerbations. In the meantime, more education on the environmental impact of inhalers may facilitate a change in prescribing habits for older children and adults.
Conclusion
With climate change having become a global emergency, it is important to explore how the healthcare sector can reduce its carbon footprint. This study indicates that many patients and practitioners are willing to consider changing to less environmentally damaging inhalers.
View Appendices.
Summary
Abstract
Aim
Inhalers are commonly used in the management of respiratory diseases. The propellants used in pressurised metered dose inhalers (pMDIs) are potent greenhouse gases and carry a substantial global warming potential. Dry powder inhalers (DPIs) are propellant-free alternatives that have fewer consequences on the environment, while being equally effective. In this study, we assessed patients’ and clinicians’ attitudes towards choosing inhalers that have a lesser environmental impact.
Method
Surveys of patients and practitioners were undertaken in primary and secondary care settings in Dunedin and Invercargill. Fifty-three patient and 16 practitioner responses were obtained.
Results
Sixty-four percent of patients were using pMDIs, while 53% were using DPIs. Sixty-nine percent of patients believed that the environment is an important consideration when switching inhalers. Sixty-three percent of practitioners were aware of the global warming potential of inhalers. Despite this, 56% of practitioners predominantly prescribe or recommend pMDIs. The 44% of practitioners who mostly prescribe DPIs were more comfortable doing so based on environmental impact alone.
Conclusion
Most respondents believe global warming is an important issue and would consider changing their inhaler to a more environmentally friendly type. Many people were not aware that pressurised metered dose inhalers have a substantial carbon footprint. Greater awareness of their environmental impacts may encourage the use of inhalers with lower global warming potential.
Author Information
Acknowledgements
Correspondence
Correspondence Email
Competing Interests
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Investigating attitudes and insights into the global warming impact of inhalers
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Obstructive airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), affect over 800,000 people in New Zealand and are major contributors to morbidity and mortality.[[1]] Inhaled medication is the mainstay of treatment for most patients.[[2–4]] There are three main types of inhalers available: pressurised metered dose inhalers (pMDIs) use a propellant to aerosolise the medication; dry powder inhalers (DPIs) contain a compacted drug powder that is broken up by inspiratory pressure when inhaled; and soft mist inhalers (SMIs) convert a liquid form of the medication into a fine spray under an external pressure.[[5,6]]
Most medication classes are available in both pMDI and DPI preparations, and studies show that these have comparable efficacies in the management of asthma and COPD in both routine day-to-day use and in emergency settings.[[7–10]] SMIs may achieve more efficient drug delivery and greater symptom improvement in patients with COPD compared to pMDIs, but fewer medications are available in this form.[[11]]
Patient factors, such as ease of use and effectiveness, are the most important consideration when choosing which type of inhaler to use: for example DPIs may not be suitable for those who cannot generate an adequate inspiratory pressure such as young children or elderly patients.[[12]] However, DPIs are associated with lower rates of errors concerning inhaler technique than pMDIs.[[13]] Similarly, most patients quickly master the correct inhaler technique for SMIs.[[14]] Cost is another consideration: while DPIs tend to be more expensive than pMDIs, most are fully subsidised in New Zealand.[[15]] Beyond these considerations, clinicians’ prescribing appear to be mostly guided by familiarity, local protocols and availability, reflected by the considerable variation in the use of pMDIs and DPIs worldwide: 70% of inhalers prescribed in England are pMDIs, compared to only 10% in Scandinavian countries.[[16]] In New Zealand, there has been a decrease in the proportion of pMDIs from 75% of dispensed inhalers in 2017 to 66% in 2020.[[15]]
Another factor that should be considered when choosing the right inhaler is the environmental impact.[[17]] The healthcare sector in OECD countries is estimated to contribute 3–8% of the nation’s total greenhouse gas emissions, and inhaled therapy makes up a substantial proportion of this.[[18–20]] The propellants presently used in pMDIs are hydrofluorocarbons (HFCs), which are potent greenhouse gases.[[21]] They are currently responsible for 3.5% of the carbon footprint of the United Kingdom’s National Health Service. Overall, these propellants are estimated to contribute 0.03% of global greenhouse gas emissions.[[22,23]] The global warming potential of one 200-actuation pMDI canister is equivalent to driving 290 kilometres in a small car.[[23]] Although there are substantial differences in the global warming potential of different propellants and the quantity contained in different inhaler brands, all current pMDIs have a much greater carbon footprint than DPIs or SMIs.[[17]] DPIs and SMIs do not contain propellants and have an approximately 95% lower carbon footprint.[[24,25]]
A 2017 study performed in London found that 80% of patients and 68% of physicians believed that the carbon footprint of inhalers was important.[[26]] There is no research looking at the opinions of prescribers and patients regarding changing inhalers for environmental reasons in New Zealand. We investigated the factors that patients and practitioners consider when making decisions relating to inhalers.
Methods
A quantitative and qualitative study was performed. We invited patients and practitioners aged 18 years or over in Dunedin or Invercargill who use, prescribe or give advice on inhalers. Patients were recruited from medical centres, hospital outpatient waiting rooms, and inpatient wards. Practitioners were contacted by email and by phone. Additionally, QR codes linked to a digital version of our questionnaire were placed in waiting areas in medical centres and hospitals. Demographic information about age, gender, ethnicity, patients’ location, disease and highest level of education, and practitioners’ role and country of training was collected. Ethnicity and gender questions were based on the 2018 and 2023 New Zealand Census.[[27,28]] Separate questionnaires were created for patients and practitioners using Qualtrics[[XM]] (Seattle, WA, USA) software, using both open-ended and structured answers (see Appendix). Questionnaires were completed online or on paper and took 5 to 10 minutes to complete. A chart was used to identify the types of inhalers.[[29]] A brief explanation of the effects of HFC inhaler propellants on the environment was provided towards the end of these questionnaires.[[30]]
Analyses were performed using GraphPad Prism 9.4.1 (GraphPad Software Inc., California, USA). Data values are expressed as mean ± standard error of the mean (SEM). Data distributions were tested for normality using a D'Agostino-Pearson test. Normally distributed measures were compared using unpaired student’s t-Tests. Non-parametric measures were compared using a Mann–Whitney U test or one-way analysis of variance (ANOVA) on ranks followed by post hoc Dunn’s multiple comparisons tests. Categorical outcomes were compared using a Chi-squared test. Statistical significance was determined as a two-sided p-value <0.05.
Informed consent was given verbally or in writing. The study was approved by the University of Otago Ethics Committee.
Results
View Figures 1–3 and Table 1.
Fifty-three patients and 16 practitioners were included (Figure 1, Table 1).
Thirty-four (64%) patients were currently using a pMDI, 28 (53%) a DPI, and 8 (15%) an SMI. Seventeen (32%) were using multiple types of inhalers. There were no differences in types of inhalers between diseases. Most patients were “somewhat satisfied” or “satisfied” with their inhalers. There was little difference in satisfaction between those only using pMDIs (75%) versus DPIs (89%).
Factors influencing patients’ willingness to change inhaler type
The most important factor for patients changing an inhaler was symptom relief, with 47/53 (89%) of people rating this as “somewhat agree” or “strongly agree”. Most patients also considered ease of use 37/53 (70%), environmental impact 36/53(68%) and cost to the healthcare system 26/53 (49%) to be important, although symptom relief scored more highly than any of these (Figure 2).
Forty-four out of 53 (83%) of patients agreed or strongly agreed that global warming is an important issue and 35/53 (66%) considered the environmental impact of the healthcare that they receive. 26/53 (49%) of patients reported being aware that inhalers had some form of environmental impact.
Patients who consider the environmental impact of their healthcare were more likely to rank the environmental impact of inhalers as important than those who did not (p=0.040). There were no substantial or statistically significant differences between those concerned about global warming or aware of the environmental impact of inhalers, or between age, gender or disease. After information was provided on the environmental impact of inhalers, there was no appreciable difference in the willingness to consider the environment when choosing inhalers.
Factors influencing practitioners’ willingness to change inhaler type
All practitioners rated symptom relief and ease of use as having “some influence” or a “strong influence” in their decision of inhaler type. These were more important than both environmental impact and cost to the healthcare system (Figure 3).
Twelve out of 16 (75%) of practitioners believed global warming to be “very” or “extremely” important, but only 10 were aware of the difference in global warming potential between pMDIs and DPIs. After being given information about the environmental impact of the different types of inhalers, the number of practitioners who said that the environment would have either some influence or a strong influence on their prescribing increased from four (25%) to 12 (75%) (p=0.029). Practitioners’ concerns around DPIs included some patients not being able to use them due to their age or severity of disease, their ease of use, not wanting to change inhalers if patients had stable disease control on pMDIs, patient preference and a lack of familiarity with DPIs.
Discussion
We found that most patients and practitioners are willing to consider environmental impacts when choosing their inhalers once they had been made aware of the differences between inhaler types. Most patients expressed willingness to change their inhaler based on environmental considerations if their doctor recommended it.
As expected, the priorities for both patients and practitioners are ease of use and efficacy or symptom control. Most people who were unwilling to change their inhaler for environmental reasons indicated that they feared their disease would get out of control. However, DPIs have been shown to be as effective as pMDIs in controlling symptoms of both asthma and COPD, and improvements in quality of life and clinical outcomes have been observed when switching asthma and COPD patients from pMDIs to DPIs.[[7–10,31]] Furthermore, while the use of a short-acting beta-agonist pMDI with a spacer is currently the first-line intervention for acute severe bronchospasm, a review of 23 randomised trials found that the administration of short-acting beta-agonist through DPIs was as effective in treating acute severe asthma as pMDI therapy, both with and without a spacer.[[2–4,32]] Therefore, there may be scope for many patients to change to DPIs without compromising symptom relief and disease control. On the other hand, young children may not be suitable for DPI therapy due to the intricacies of their use and the lack of evidence in this age group.[[33]] All paediatricians in this study said that they prescribe pMDIs most frequently. Older children have been shown to use DPIs effectively and may be suitable for a trial of DPI therapy, but there are few studies of this.[[33]] Future reductions in the environmental impact of pMDI use in this age group could eventually be achieved through the use pMDI propellants with a lower global warming potential. These are currently being developed, but it will be several years before these become available.[[17,34]]
Most participants thought that global warming was an important issue, and two thirds considered the environmental impact of the healthcare they receive. However, only half of the participants were aware of the impact that inhalers have on the environment. Educating patients about this issue to increase awareness may influence future healthcare decisions to reduce global warming and environmental harm. However, we did not find that providing brief written information on the global warming potential of different inhalers made any immediate difference to patient attitudes to inhaler choices.
The wider environmental impact of inhaled treatment is less well understood. Although pMDIs have much greater overall global warming effects due to their hydrofluorocarbons propellants,[[7–10,24]] the full life cycle of DPIs may have greater impacts on fossil depletion, terrestrial acidification, freshwater and marine eutrophication and ecotoxicity, and the formation of photochemical oxidants due to the use of greater amounts of plastic and raw materials in their manufacture.[[24]] Future improvements in inhaler manufacture and reuse/recyclability of these inhalers may reduce these impacts.[[17]] However, none of these are as urgent as reducing the global warming potential of inhalers in the face of the current climate emergency. Another drawback is that many DPI inhaler devices are patented, making it more difficult to replace them with cheaper generic drugs, although most classes of drug now have several alternative preparations. As noted above, new propellants with a lower global warming potential may eventually make pMDIs an environmentally friendly and cost-effective choice.
Most hospital-based physicians and nurse specialists were aware of the difference in global warming potential between inhaler types, although providing written information did appear to increase the influence of environmental impacts of their inhaler choices. Ease of use and efficacy of the inhaler are the most important factors to consider when choosing inhalers. However, switching patients from pMDI- to DPI-based maintenance therapy reduces the annual inhaler carbon footprint by 55% without loss of asthma control.[[10]] Good disease control is important for environmental as well as clinical reasons: suboptimal disease control resulting in overuse of relieving medications may contribute to two thirds of greenhouse gas emissions from inhalers.[[35]]
To our knowledge, this is the first New Zealand study into environmental influences on inhaler prescribing and patient preferences regarding inhaler choices. Strengths include using both quantitative and qualitative techniques to gain a greater understanding of these factors. Interviewer bias was minimised by using standardised questionnaires, however, we did not validate the questionnaires and having multiple interviewers meant that it is possible that there were subtle differences in how participants were asked the questions. Social desirability bias may have resulted in a higher estimate of participants that consider the environment to be an issue compared to the actual population. Many patients were excluded for practical reasons (such as infection control or frailty), and we recruited only a small proportion of the practitioners that we approached. Other limitations of this study include an overrepresentation of inpatients, and the single-area setting (Southern), which led to a mostly older patient group with a higher proportion of NZ Europeans than the whole of New Zealand.[[36]] This is important because Māori and Pacific people experience a higher burden of respiratory disease. It would be informative to investigate these issues with different age and ethic patient groups and a larger sample of practitioners. We also need research on the efficacy of DPIs in young children and more data on their use in acute asthma exacerbations. In the meantime, more education on the environmental impact of inhalers may facilitate a change in prescribing habits for older children and adults.
Conclusion
With climate change having become a global emergency, it is important to explore how the healthcare sector can reduce its carbon footprint. This study indicates that many patients and practitioners are willing to consider changing to less environmentally damaging inhalers.
View Appendices.
Summary
Abstract
Aim
Inhalers are commonly used in the management of respiratory diseases. The propellants used in pressurised metered dose inhalers (pMDIs) are potent greenhouse gases and carry a substantial global warming potential. Dry powder inhalers (DPIs) are propellant-free alternatives that have fewer consequences on the environment, while being equally effective. In this study, we assessed patients’ and clinicians’ attitudes towards choosing inhalers that have a lesser environmental impact.
Method
Surveys of patients and practitioners were undertaken in primary and secondary care settings in Dunedin and Invercargill. Fifty-three patient and 16 practitioner responses were obtained.
Results
Sixty-four percent of patients were using pMDIs, while 53% were using DPIs. Sixty-nine percent of patients believed that the environment is an important consideration when switching inhalers. Sixty-three percent of practitioners were aware of the global warming potential of inhalers. Despite this, 56% of practitioners predominantly prescribe or recommend pMDIs. The 44% of practitioners who mostly prescribe DPIs were more comfortable doing so based on environmental impact alone.
Conclusion
Most respondents believe global warming is an important issue and would consider changing their inhaler to a more environmentally friendly type. Many people were not aware that pressurised metered dose inhalers have a substantial carbon footprint. Greater awareness of their environmental impacts may encourage the use of inhalers with lower global warming potential.
Author Information
Acknowledgements
Correspondence
Correspondence Email
Competing Interests
1) Barnard LT, Zhang J. The impact of respiratory disease in New Zealand: 2020 update. Asthma and Respiratory Foundation NZ; 2021.
2) Beasley R, Beckert L, Fingleton J, et al. Asthma and Respiratory Foundation NZ Adolescent and Adult Asthma Guidelines 2020: a quick reference guide. N Z Med J. 2020 Jun 26;133(1517):73-99.
3) McNamara D, Asher I, Davies C, et al. NZ child asthma guidelines: A quick reference guide. Asthma and Respiratory Foundation NZ; 2020.
4) New Zealand COPD Guidelines: Quick Reference Guide. N Z Med J. 2021 Feb 19;134(1530):76-110.
5) Ponen S. Inhaler devices [Internet]. 2018. Available from: https://www.healthnavigator.org.nz/medicines/i/inhaler-devices/.
6) Levy ML, Carroll W, Izquierdo Alonso JL, et al. Understanding Dry Powder Inhalers: Key Technical and Patient Preference Attributes. Adv Ther. 2019 Oct;36(10):2547-2557.
7) Beeh KM, Kuna P, Corradi M, et al. Comparison of Dry-Powder Inhaler and Pressurized Metered-Dose Inhaler Formulations of Extrafine Beclomethasone Dipropionate/Formoterol Fumarate/Glycopyrronium in Patients with COPD: The TRI-D Randomized Controlled Trial. Int J Chron Obstruct Pulmon Dis. 2021 Jan 14;16:79-89.
8) Woo SD, Ye YM, Lee Y, et al. Efficacy and Safety of a Pressurized Metered-Dose Inhaler in Older Asthmatics: Comparison to a Dry Powder Inhaler in a 12-Week Randomized Trial. Allergy Asthma Immunol Res. 2020 May;12(3):454-466.
9) Selroos O, Borgström L, Ingelf J. Use of dry powder inhalers in acute exacerbations of asthma and COPD. Ther Adv Respir Dis. 2009 Apr;3(2):81-91.
10) Woodcock A, Janson C, Rees J, et al. Effects of switching from a metered dose inhaler to a dry powder inhaler on climate emissions and asthma control: post-hoc analysis. Thorax. 2022;77:1187-1192.
11) Voshaar T, Lapidus R, Maleki-Yazdi R, et al. A randomized study of tiotropium Respimat Soft Mist inhaler vs. ipratropium pMDI in COPD. Respir Med. 2008 Jan;102(1):32-41.
12) The Confusing World of Dry Powder Inhalers: It Is All About Inspiratory Pressures, Not Inspiratory Flow Rates. J Aerosol Med Pulm Drug Deliv. 2020 Feb;33(1):1-11.
13) Ramadan WH, Sarkis AT. Patterns of use of dry powder inhalers versus pressurized metered-dose inhalers devices in adult patients with chronic obstructive pulmonary disease or asthma: An observational comparative study. Chron Respir Dis. 2017;14(3):309-20.
14) Iwanaga T, Tohda Y, Nakamura S, et al. The Respimat® Soft Mist Inhaler: Implications of Drug Delivery Characteristics for Patients. Clin Drug Investig. 2019 Nov;39(11):1021-1030.
15) Pharmac. Number and cost of metered dose and dry powder inhalers and devices dispensed each year from 2017 to 2020 [Internet]. 2021 [cited 2022 Jul 29]. Available from: https://pharmac.govt.nz/news-and-resources/official-information-act/official-information-act-responses/number-and-cost-of-metered-dose-and-dry-powder-inhalers-and-devices-dispensed-each-year-from-2017-to-2020/.
16) Hillman T, Mortimer F, Hopkinson NS. Inhaled drugs and global warming: time to shift to dry powder inhalers. BMJ. 2013 May 28;346:f3359.
17) Woodcock A, Beeh KM, Sagara H, et al. The environmental impact of inhaled therapy: Making informed treatment choices. Eur Respir J. 2022;60(1:)2102-106.
18) Mercer C. How health care contributes to climate change. CMAJ. 2019;191(14):E403-E404.
19) Beehive.govt.nz [Internet]. Genter JA. Healthcare sector committed to reducing carbon footprint [Media release]. 2018 [cited 2022 Aug 2]. Available from: https://www.beehive.govt.nz/release/healthcare-sector-committed-reducing-carbon-footprint#:~:text=%E2%80%9CIt%20is%20estimated%20New%20Zealand's,Zealand's%20total%20greenhouse%20gas%20emissions.
20) Eckelman MJ, Huang K, Lagasse R, et al. Health Care Pollution And Public Health Damage In The United States: An Update. Health Aff (Millwood). 2020 Dec;39(12):2071-2079.
21) Newman SP. Principles of metered-dose inhaler design. Respir Care. 2005;50(9):1177-90.
22) Starup-Hansen J, Dunne H, Sadler J, et al. Climate change in healthcare: Exploring the potential role of inhaler prescribing. Pharmacol Res Perspect. 2020;8(6):e00675.
23) United Nations Environment Programme [Internet]. Montreal Protocol On Substances That Deplete The Ozone Layer: UNEP 2014 report of the medical technical options committee. Nairobi, Kenya; 2015 [cited 20 Oct 2022]. Available from: http://ozone.unep.org/en/assessment_panels_bodies.php.
24) Jeswani HK, Azapagic A. Life cycle environmental impacts of inhalers. J Clean Prod. 2019;237:117733.
25) Hänsel M, Bambach T, Wachtel H. Reduced Environmental Impact of the Reusable Respimat® Soft Mist™ Inhaler Compared with Pressurised Metered-Dose Inhalers. Adv Ther. 2019;36(9):2487-92.
26) Liew KL, Wilkinson A. P280 how do we choose inhalers? patient and physician perspectives on environmental, financial and ease-of-use factors. Thorax. 2017;72:A235-A237.
27) Stats NZ [Internet]. 2018 census ethnic groups dataset. 2020 [cited 2022 Aug 8]. Available from: https://www.stats.govt.nz/information-releases/2018-census-ethnic-groups-dataset/.
28) Stats NZ [Internet]. Statistical standard for gender, sex, and variations of sex characteristics. 2021 [cited 2022 Aug 8]. Available from: https://www.stats.govt.nz/methods/statistical-standard-for-gender-sex-and-variations-of-sex-characteristics.
29) Clinical Pharmacy Department [Internet]. Inhaler devices identification chart. Auckland: Counties Manukau Health; 2020 [cited 20 Oct 2022]. Available from: https://canvas.manukau.ac.nz/courses/48106.
30) National Institute for Health and care Excellence [Internet]. Patient decision aid: Inhalers for asthma. National Institute for Health and Care Excellence; 2020 [cited 30 Mar 2023]. Available from: https://www.nice.org.uk/guidance/ng80/resources/inhalers-for-asthma-patient-decision-aid-pdf-6727144573?UID=336247463202232945141.
31) Doyle C, Lennox L, Bell D. A systematic review of evidence on the links between patient experience and clinical safety and effectiveness. BMJ Open. 2013;3:e001570.
32) Selroos O. Dry-powder inhalers in acute asthma. Ther Deliv. 2014;5(1):69-81.
33) Hatter L, Bruce P, Beasley R. A breath of fresh AIR: Reducing the carbon footprint of asthma. J Med Econ. 2022 Jan-Dec;25(1):700-702.
34) AstraZeneca [Internet]. AstraZeneca progresses Ambition Zero Carbon programme with Honeywell partnership to develop next-generation respiratory inhalers. 2022 [cited 2022 Aug 12]. Available from: https://www.astrazeneca.com/media-centre/press-releases/2022/astrazeneca-progresses-ambition-zero-carbon-programme-with-honeywell-partnership-to-develop-next-generation-respiratory-inhalers.html.
35) Janson C, Maslova E, Wilkinson A, et al. The carbon footprint of respiratory treatments in Europe and Canada: an observational study from the carbon programme. Eur Respir J. 2022 Aug 10;60(2):2102760.
36) Environmental Health Intelligence New Zealand [Internet]. Ethnic profile. 2020 [cited 2022 Aug 10]. https://www.ehinz.ac.nz/indicators/population-vulnerability/ethnic-profile/.
For the PDF of this article,
contact nzmj@nzma.org.nz
Investigating attitudes and insights into the global warming impact of inhalers
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Obstructive airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), affect over 800,000 people in New Zealand and are major contributors to morbidity and mortality.[[1]] Inhaled medication is the mainstay of treatment for most patients.[[2–4]] There are three main types of inhalers available: pressurised metered dose inhalers (pMDIs) use a propellant to aerosolise the medication; dry powder inhalers (DPIs) contain a compacted drug powder that is broken up by inspiratory pressure when inhaled; and soft mist inhalers (SMIs) convert a liquid form of the medication into a fine spray under an external pressure.[[5,6]]
Most medication classes are available in both pMDI and DPI preparations, and studies show that these have comparable efficacies in the management of asthma and COPD in both routine day-to-day use and in emergency settings.[[7–10]] SMIs may achieve more efficient drug delivery and greater symptom improvement in patients with COPD compared to pMDIs, but fewer medications are available in this form.[[11]]
Patient factors, such as ease of use and effectiveness, are the most important consideration when choosing which type of inhaler to use: for example DPIs may not be suitable for those who cannot generate an adequate inspiratory pressure such as young children or elderly patients.[[12]] However, DPIs are associated with lower rates of errors concerning inhaler technique than pMDIs.[[13]] Similarly, most patients quickly master the correct inhaler technique for SMIs.[[14]] Cost is another consideration: while DPIs tend to be more expensive than pMDIs, most are fully subsidised in New Zealand.[[15]] Beyond these considerations, clinicians’ prescribing appear to be mostly guided by familiarity, local protocols and availability, reflected by the considerable variation in the use of pMDIs and DPIs worldwide: 70% of inhalers prescribed in England are pMDIs, compared to only 10% in Scandinavian countries.[[16]] In New Zealand, there has been a decrease in the proportion of pMDIs from 75% of dispensed inhalers in 2017 to 66% in 2020.[[15]]
Another factor that should be considered when choosing the right inhaler is the environmental impact.[[17]] The healthcare sector in OECD countries is estimated to contribute 3–8% of the nation’s total greenhouse gas emissions, and inhaled therapy makes up a substantial proportion of this.[[18–20]] The propellants presently used in pMDIs are hydrofluorocarbons (HFCs), which are potent greenhouse gases.[[21]] They are currently responsible for 3.5% of the carbon footprint of the United Kingdom’s National Health Service. Overall, these propellants are estimated to contribute 0.03% of global greenhouse gas emissions.[[22,23]] The global warming potential of one 200-actuation pMDI canister is equivalent to driving 290 kilometres in a small car.[[23]] Although there are substantial differences in the global warming potential of different propellants and the quantity contained in different inhaler brands, all current pMDIs have a much greater carbon footprint than DPIs or SMIs.[[17]] DPIs and SMIs do not contain propellants and have an approximately 95% lower carbon footprint.[[24,25]]
A 2017 study performed in London found that 80% of patients and 68% of physicians believed that the carbon footprint of inhalers was important.[[26]] There is no research looking at the opinions of prescribers and patients regarding changing inhalers for environmental reasons in New Zealand. We investigated the factors that patients and practitioners consider when making decisions relating to inhalers.
Methods
A quantitative and qualitative study was performed. We invited patients and practitioners aged 18 years or over in Dunedin or Invercargill who use, prescribe or give advice on inhalers. Patients were recruited from medical centres, hospital outpatient waiting rooms, and inpatient wards. Practitioners were contacted by email and by phone. Additionally, QR codes linked to a digital version of our questionnaire were placed in waiting areas in medical centres and hospitals. Demographic information about age, gender, ethnicity, patients’ location, disease and highest level of education, and practitioners’ role and country of training was collected. Ethnicity and gender questions were based on the 2018 and 2023 New Zealand Census.[[27,28]] Separate questionnaires were created for patients and practitioners using Qualtrics[[XM]] (Seattle, WA, USA) software, using both open-ended and structured answers (see Appendix). Questionnaires were completed online or on paper and took 5 to 10 minutes to complete. A chart was used to identify the types of inhalers.[[29]] A brief explanation of the effects of HFC inhaler propellants on the environment was provided towards the end of these questionnaires.[[30]]
Analyses were performed using GraphPad Prism 9.4.1 (GraphPad Software Inc., California, USA). Data values are expressed as mean ± standard error of the mean (SEM). Data distributions were tested for normality using a D'Agostino-Pearson test. Normally distributed measures were compared using unpaired student’s t-Tests. Non-parametric measures were compared using a Mann–Whitney U test or one-way analysis of variance (ANOVA) on ranks followed by post hoc Dunn’s multiple comparisons tests. Categorical outcomes were compared using a Chi-squared test. Statistical significance was determined as a two-sided p-value <0.05.
Informed consent was given verbally or in writing. The study was approved by the University of Otago Ethics Committee.
Results
View Figures 1–3 and Table 1.
Fifty-three patients and 16 practitioners were included (Figure 1, Table 1).
Thirty-four (64%) patients were currently using a pMDI, 28 (53%) a DPI, and 8 (15%) an SMI. Seventeen (32%) were using multiple types of inhalers. There were no differences in types of inhalers between diseases. Most patients were “somewhat satisfied” or “satisfied” with their inhalers. There was little difference in satisfaction between those only using pMDIs (75%) versus DPIs (89%).
Factors influencing patients’ willingness to change inhaler type
The most important factor for patients changing an inhaler was symptom relief, with 47/53 (89%) of people rating this as “somewhat agree” or “strongly agree”. Most patients also considered ease of use 37/53 (70%), environmental impact 36/53(68%) and cost to the healthcare system 26/53 (49%) to be important, although symptom relief scored more highly than any of these (Figure 2).
Forty-four out of 53 (83%) of patients agreed or strongly agreed that global warming is an important issue and 35/53 (66%) considered the environmental impact of the healthcare that they receive. 26/53 (49%) of patients reported being aware that inhalers had some form of environmental impact.
Patients who consider the environmental impact of their healthcare were more likely to rank the environmental impact of inhalers as important than those who did not (p=0.040). There were no substantial or statistically significant differences between those concerned about global warming or aware of the environmental impact of inhalers, or between age, gender or disease. After information was provided on the environmental impact of inhalers, there was no appreciable difference in the willingness to consider the environment when choosing inhalers.
Factors influencing practitioners’ willingness to change inhaler type
All practitioners rated symptom relief and ease of use as having “some influence” or a “strong influence” in their decision of inhaler type. These were more important than both environmental impact and cost to the healthcare system (Figure 3).
Twelve out of 16 (75%) of practitioners believed global warming to be “very” or “extremely” important, but only 10 were aware of the difference in global warming potential between pMDIs and DPIs. After being given information about the environmental impact of the different types of inhalers, the number of practitioners who said that the environment would have either some influence or a strong influence on their prescribing increased from four (25%) to 12 (75%) (p=0.029). Practitioners’ concerns around DPIs included some patients not being able to use them due to their age or severity of disease, their ease of use, not wanting to change inhalers if patients had stable disease control on pMDIs, patient preference and a lack of familiarity with DPIs.
Discussion
We found that most patients and practitioners are willing to consider environmental impacts when choosing their inhalers once they had been made aware of the differences between inhaler types. Most patients expressed willingness to change their inhaler based on environmental considerations if their doctor recommended it.
As expected, the priorities for both patients and practitioners are ease of use and efficacy or symptom control. Most people who were unwilling to change their inhaler for environmental reasons indicated that they feared their disease would get out of control. However, DPIs have been shown to be as effective as pMDIs in controlling symptoms of both asthma and COPD, and improvements in quality of life and clinical outcomes have been observed when switching asthma and COPD patients from pMDIs to DPIs.[[7–10,31]] Furthermore, while the use of a short-acting beta-agonist pMDI with a spacer is currently the first-line intervention for acute severe bronchospasm, a review of 23 randomised trials found that the administration of short-acting beta-agonist through DPIs was as effective in treating acute severe asthma as pMDI therapy, both with and without a spacer.[[2–4,32]] Therefore, there may be scope for many patients to change to DPIs without compromising symptom relief and disease control. On the other hand, young children may not be suitable for DPI therapy due to the intricacies of their use and the lack of evidence in this age group.[[33]] All paediatricians in this study said that they prescribe pMDIs most frequently. Older children have been shown to use DPIs effectively and may be suitable for a trial of DPI therapy, but there are few studies of this.[[33]] Future reductions in the environmental impact of pMDI use in this age group could eventually be achieved through the use pMDI propellants with a lower global warming potential. These are currently being developed, but it will be several years before these become available.[[17,34]]
Most participants thought that global warming was an important issue, and two thirds considered the environmental impact of the healthcare they receive. However, only half of the participants were aware of the impact that inhalers have on the environment. Educating patients about this issue to increase awareness may influence future healthcare decisions to reduce global warming and environmental harm. However, we did not find that providing brief written information on the global warming potential of different inhalers made any immediate difference to patient attitudes to inhaler choices.
The wider environmental impact of inhaled treatment is less well understood. Although pMDIs have much greater overall global warming effects due to their hydrofluorocarbons propellants,[[7–10,24]] the full life cycle of DPIs may have greater impacts on fossil depletion, terrestrial acidification, freshwater and marine eutrophication and ecotoxicity, and the formation of photochemical oxidants due to the use of greater amounts of plastic and raw materials in their manufacture.[[24]] Future improvements in inhaler manufacture and reuse/recyclability of these inhalers may reduce these impacts.[[17]] However, none of these are as urgent as reducing the global warming potential of inhalers in the face of the current climate emergency. Another drawback is that many DPI inhaler devices are patented, making it more difficult to replace them with cheaper generic drugs, although most classes of drug now have several alternative preparations. As noted above, new propellants with a lower global warming potential may eventually make pMDIs an environmentally friendly and cost-effective choice.
Most hospital-based physicians and nurse specialists were aware of the difference in global warming potential between inhaler types, although providing written information did appear to increase the influence of environmental impacts of their inhaler choices. Ease of use and efficacy of the inhaler are the most important factors to consider when choosing inhalers. However, switching patients from pMDI- to DPI-based maintenance therapy reduces the annual inhaler carbon footprint by 55% without loss of asthma control.[[10]] Good disease control is important for environmental as well as clinical reasons: suboptimal disease control resulting in overuse of relieving medications may contribute to two thirds of greenhouse gas emissions from inhalers.[[35]]
To our knowledge, this is the first New Zealand study into environmental influences on inhaler prescribing and patient preferences regarding inhaler choices. Strengths include using both quantitative and qualitative techniques to gain a greater understanding of these factors. Interviewer bias was minimised by using standardised questionnaires, however, we did not validate the questionnaires and having multiple interviewers meant that it is possible that there were subtle differences in how participants were asked the questions. Social desirability bias may have resulted in a higher estimate of participants that consider the environment to be an issue compared to the actual population. Many patients were excluded for practical reasons (such as infection control or frailty), and we recruited only a small proportion of the practitioners that we approached. Other limitations of this study include an overrepresentation of inpatients, and the single-area setting (Southern), which led to a mostly older patient group with a higher proportion of NZ Europeans than the whole of New Zealand.[[36]] This is important because Māori and Pacific people experience a higher burden of respiratory disease. It would be informative to investigate these issues with different age and ethic patient groups and a larger sample of practitioners. We also need research on the efficacy of DPIs in young children and more data on their use in acute asthma exacerbations. In the meantime, more education on the environmental impact of inhalers may facilitate a change in prescribing habits for older children and adults.
Conclusion
With climate change having become a global emergency, it is important to explore how the healthcare sector can reduce its carbon footprint. This study indicates that many patients and practitioners are willing to consider changing to less environmentally damaging inhalers.
View Appendices.
Summary
Abstract
Aim
Inhalers are commonly used in the management of respiratory diseases. The propellants used in pressurised metered dose inhalers (pMDIs) are potent greenhouse gases and carry a substantial global warming potential. Dry powder inhalers (DPIs) are propellant-free alternatives that have fewer consequences on the environment, while being equally effective. In this study, we assessed patients’ and clinicians’ attitudes towards choosing inhalers that have a lesser environmental impact.
Method
Surveys of patients and practitioners were undertaken in primary and secondary care settings in Dunedin and Invercargill. Fifty-three patient and 16 practitioner responses were obtained.
Results
Sixty-four percent of patients were using pMDIs, while 53% were using DPIs. Sixty-nine percent of patients believed that the environment is an important consideration when switching inhalers. Sixty-three percent of practitioners were aware of the global warming potential of inhalers. Despite this, 56% of practitioners predominantly prescribe or recommend pMDIs. The 44% of practitioners who mostly prescribe DPIs were more comfortable doing so based on environmental impact alone.
Conclusion
Most respondents believe global warming is an important issue and would consider changing their inhaler to a more environmentally friendly type. Many people were not aware that pressurised metered dose inhalers have a substantial carbon footprint. Greater awareness of their environmental impacts may encourage the use of inhalers with lower global warming potential.
Author Information
Acknowledgements
Correspondence
Correspondence Email
Competing Interests
1) Barnard LT, Zhang J. The impact of respiratory disease in New Zealand: 2020 update. Asthma and Respiratory Foundation NZ; 2021.
2) Beasley R, Beckert L, Fingleton J, et al. Asthma and Respiratory Foundation NZ Adolescent and Adult Asthma Guidelines 2020: a quick reference guide. N Z Med J. 2020 Jun 26;133(1517):73-99.
3) McNamara D, Asher I, Davies C, et al. NZ child asthma guidelines: A quick reference guide. Asthma and Respiratory Foundation NZ; 2020.
4) New Zealand COPD Guidelines: Quick Reference Guide. N Z Med J. 2021 Feb 19;134(1530):76-110.
5) Ponen S. Inhaler devices [Internet]. 2018. Available from: https://www.healthnavigator.org.nz/medicines/i/inhaler-devices/.
6) Levy ML, Carroll W, Izquierdo Alonso JL, et al. Understanding Dry Powder Inhalers: Key Technical and Patient Preference Attributes. Adv Ther. 2019 Oct;36(10):2547-2557.
7) Beeh KM, Kuna P, Corradi M, et al. Comparison of Dry-Powder Inhaler and Pressurized Metered-Dose Inhaler Formulations of Extrafine Beclomethasone Dipropionate/Formoterol Fumarate/Glycopyrronium in Patients with COPD: The TRI-D Randomized Controlled Trial. Int J Chron Obstruct Pulmon Dis. 2021 Jan 14;16:79-89.
8) Woo SD, Ye YM, Lee Y, et al. Efficacy and Safety of a Pressurized Metered-Dose Inhaler in Older Asthmatics: Comparison to a Dry Powder Inhaler in a 12-Week Randomized Trial. Allergy Asthma Immunol Res. 2020 May;12(3):454-466.
9) Selroos O, Borgström L, Ingelf J. Use of dry powder inhalers in acute exacerbations of asthma and COPD. Ther Adv Respir Dis. 2009 Apr;3(2):81-91.
10) Woodcock A, Janson C, Rees J, et al. Effects of switching from a metered dose inhaler to a dry powder inhaler on climate emissions and asthma control: post-hoc analysis. Thorax. 2022;77:1187-1192.
11) Voshaar T, Lapidus R, Maleki-Yazdi R, et al. A randomized study of tiotropium Respimat Soft Mist inhaler vs. ipratropium pMDI in COPD. Respir Med. 2008 Jan;102(1):32-41.
12) The Confusing World of Dry Powder Inhalers: It Is All About Inspiratory Pressures, Not Inspiratory Flow Rates. J Aerosol Med Pulm Drug Deliv. 2020 Feb;33(1):1-11.
13) Ramadan WH, Sarkis AT. Patterns of use of dry powder inhalers versus pressurized metered-dose inhalers devices in adult patients with chronic obstructive pulmonary disease or asthma: An observational comparative study. Chron Respir Dis. 2017;14(3):309-20.
14) Iwanaga T, Tohda Y, Nakamura S, et al. The Respimat® Soft Mist Inhaler: Implications of Drug Delivery Characteristics for Patients. Clin Drug Investig. 2019 Nov;39(11):1021-1030.
15) Pharmac. Number and cost of metered dose and dry powder inhalers and devices dispensed each year from 2017 to 2020 [Internet]. 2021 [cited 2022 Jul 29]. Available from: https://pharmac.govt.nz/news-and-resources/official-information-act/official-information-act-responses/number-and-cost-of-metered-dose-and-dry-powder-inhalers-and-devices-dispensed-each-year-from-2017-to-2020/.
16) Hillman T, Mortimer F, Hopkinson NS. Inhaled drugs and global warming: time to shift to dry powder inhalers. BMJ. 2013 May 28;346:f3359.
17) Woodcock A, Beeh KM, Sagara H, et al. The environmental impact of inhaled therapy: Making informed treatment choices. Eur Respir J. 2022;60(1:)2102-106.
18) Mercer C. How health care contributes to climate change. CMAJ. 2019;191(14):E403-E404.
19) Beehive.govt.nz [Internet]. Genter JA. Healthcare sector committed to reducing carbon footprint [Media release]. 2018 [cited 2022 Aug 2]. Available from: https://www.beehive.govt.nz/release/healthcare-sector-committed-reducing-carbon-footprint#:~:text=%E2%80%9CIt%20is%20estimated%20New%20Zealand's,Zealand's%20total%20greenhouse%20gas%20emissions.
20) Eckelman MJ, Huang K, Lagasse R, et al. Health Care Pollution And Public Health Damage In The United States: An Update. Health Aff (Millwood). 2020 Dec;39(12):2071-2079.
21) Newman SP. Principles of metered-dose inhaler design. Respir Care. 2005;50(9):1177-90.
22) Starup-Hansen J, Dunne H, Sadler J, et al. Climate change in healthcare: Exploring the potential role of inhaler prescribing. Pharmacol Res Perspect. 2020;8(6):e00675.
23) United Nations Environment Programme [Internet]. Montreal Protocol On Substances That Deplete The Ozone Layer: UNEP 2014 report of the medical technical options committee. Nairobi, Kenya; 2015 [cited 20 Oct 2022]. Available from: http://ozone.unep.org/en/assessment_panels_bodies.php.
24) Jeswani HK, Azapagic A. Life cycle environmental impacts of inhalers. J Clean Prod. 2019;237:117733.
25) Hänsel M, Bambach T, Wachtel H. Reduced Environmental Impact of the Reusable Respimat® Soft Mist™ Inhaler Compared with Pressurised Metered-Dose Inhalers. Adv Ther. 2019;36(9):2487-92.
26) Liew KL, Wilkinson A. P280 how do we choose inhalers? patient and physician perspectives on environmental, financial and ease-of-use factors. Thorax. 2017;72:A235-A237.
27) Stats NZ [Internet]. 2018 census ethnic groups dataset. 2020 [cited 2022 Aug 8]. Available from: https://www.stats.govt.nz/information-releases/2018-census-ethnic-groups-dataset/.
28) Stats NZ [Internet]. Statistical standard for gender, sex, and variations of sex characteristics. 2021 [cited 2022 Aug 8]. Available from: https://www.stats.govt.nz/methods/statistical-standard-for-gender-sex-and-variations-of-sex-characteristics.
29) Clinical Pharmacy Department [Internet]. Inhaler devices identification chart. Auckland: Counties Manukau Health; 2020 [cited 20 Oct 2022]. Available from: https://canvas.manukau.ac.nz/courses/48106.
30) National Institute for Health and care Excellence [Internet]. Patient decision aid: Inhalers for asthma. National Institute for Health and Care Excellence; 2020 [cited 30 Mar 2023]. Available from: https://www.nice.org.uk/guidance/ng80/resources/inhalers-for-asthma-patient-decision-aid-pdf-6727144573?UID=336247463202232945141.
31) Doyle C, Lennox L, Bell D. A systematic review of evidence on the links between patient experience and clinical safety and effectiveness. BMJ Open. 2013;3:e001570.
32) Selroos O. Dry-powder inhalers in acute asthma. Ther Deliv. 2014;5(1):69-81.
33) Hatter L, Bruce P, Beasley R. A breath of fresh AIR: Reducing the carbon footprint of asthma. J Med Econ. 2022 Jan-Dec;25(1):700-702.
34) AstraZeneca [Internet]. AstraZeneca progresses Ambition Zero Carbon programme with Honeywell partnership to develop next-generation respiratory inhalers. 2022 [cited 2022 Aug 12]. Available from: https://www.astrazeneca.com/media-centre/press-releases/2022/astrazeneca-progresses-ambition-zero-carbon-programme-with-honeywell-partnership-to-develop-next-generation-respiratory-inhalers.html.
35) Janson C, Maslova E, Wilkinson A, et al. The carbon footprint of respiratory treatments in Europe and Canada: an observational study from the carbon programme. Eur Respir J. 2022 Aug 10;60(2):2102760.
36) Environmental Health Intelligence New Zealand [Internet]. Ethnic profile. 2020 [cited 2022 Aug 10]. https://www.ehinz.ac.nz/indicators/population-vulnerability/ethnic-profile/.
Contact diana@nzma.org.nz
for the PDF of this article
Investigating attitudes and insights into the global warming impact of inhalers
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Obstructive airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), affect over 800,000 people in New Zealand and are major contributors to morbidity and mortality.[[1]] Inhaled medication is the mainstay of treatment for most patients.[[2–4]] There are three main types of inhalers available: pressurised metered dose inhalers (pMDIs) use a propellant to aerosolise the medication; dry powder inhalers (DPIs) contain a compacted drug powder that is broken up by inspiratory pressure when inhaled; and soft mist inhalers (SMIs) convert a liquid form of the medication into a fine spray under an external pressure.[[5,6]]
Most medication classes are available in both pMDI and DPI preparations, and studies show that these have comparable efficacies in the management of asthma and COPD in both routine day-to-day use and in emergency settings.[[7–10]] SMIs may achieve more efficient drug delivery and greater symptom improvement in patients with COPD compared to pMDIs, but fewer medications are available in this form.[[11]]
Patient factors, such as ease of use and effectiveness, are the most important consideration when choosing which type of inhaler to use: for example DPIs may not be suitable for those who cannot generate an adequate inspiratory pressure such as young children or elderly patients.[[12]] However, DPIs are associated with lower rates of errors concerning inhaler technique than pMDIs.[[13]] Similarly, most patients quickly master the correct inhaler technique for SMIs.[[14]] Cost is another consideration: while DPIs tend to be more expensive than pMDIs, most are fully subsidised in New Zealand.[[15]] Beyond these considerations, clinicians’ prescribing appear to be mostly guided by familiarity, local protocols and availability, reflected by the considerable variation in the use of pMDIs and DPIs worldwide: 70% of inhalers prescribed in England are pMDIs, compared to only 10% in Scandinavian countries.[[16]] In New Zealand, there has been a decrease in the proportion of pMDIs from 75% of dispensed inhalers in 2017 to 66% in 2020.[[15]]
Another factor that should be considered when choosing the right inhaler is the environmental impact.[[17]] The healthcare sector in OECD countries is estimated to contribute 3–8% of the nation’s total greenhouse gas emissions, and inhaled therapy makes up a substantial proportion of this.[[18–20]] The propellants presently used in pMDIs are hydrofluorocarbons (HFCs), which are potent greenhouse gases.[[21]] They are currently responsible for 3.5% of the carbon footprint of the United Kingdom’s National Health Service. Overall, these propellants are estimated to contribute 0.03% of global greenhouse gas emissions.[[22,23]] The global warming potential of one 200-actuation pMDI canister is equivalent to driving 290 kilometres in a small car.[[23]] Although there are substantial differences in the global warming potential of different propellants and the quantity contained in different inhaler brands, all current pMDIs have a much greater carbon footprint than DPIs or SMIs.[[17]] DPIs and SMIs do not contain propellants and have an approximately 95% lower carbon footprint.[[24,25]]
A 2017 study performed in London found that 80% of patients and 68% of physicians believed that the carbon footprint of inhalers was important.[[26]] There is no research looking at the opinions of prescribers and patients regarding changing inhalers for environmental reasons in New Zealand. We investigated the factors that patients and practitioners consider when making decisions relating to inhalers.
Methods
A quantitative and qualitative study was performed. We invited patients and practitioners aged 18 years or over in Dunedin or Invercargill who use, prescribe or give advice on inhalers. Patients were recruited from medical centres, hospital outpatient waiting rooms, and inpatient wards. Practitioners were contacted by email and by phone. Additionally, QR codes linked to a digital version of our questionnaire were placed in waiting areas in medical centres and hospitals. Demographic information about age, gender, ethnicity, patients’ location, disease and highest level of education, and practitioners’ role and country of training was collected. Ethnicity and gender questions were based on the 2018 and 2023 New Zealand Census.[[27,28]] Separate questionnaires were created for patients and practitioners using Qualtrics[[XM]] (Seattle, WA, USA) software, using both open-ended and structured answers (see Appendix). Questionnaires were completed online or on paper and took 5 to 10 minutes to complete. A chart was used to identify the types of inhalers.[[29]] A brief explanation of the effects of HFC inhaler propellants on the environment was provided towards the end of these questionnaires.[[30]]
Analyses were performed using GraphPad Prism 9.4.1 (GraphPad Software Inc., California, USA). Data values are expressed as mean ± standard error of the mean (SEM). Data distributions were tested for normality using a D'Agostino-Pearson test. Normally distributed measures were compared using unpaired student’s t-Tests. Non-parametric measures were compared using a Mann–Whitney U test or one-way analysis of variance (ANOVA) on ranks followed by post hoc Dunn’s multiple comparisons tests. Categorical outcomes were compared using a Chi-squared test. Statistical significance was determined as a two-sided p-value <0.05.
Informed consent was given verbally or in writing. The study was approved by the University of Otago Ethics Committee.
Results
View Figures 1–3 and Table 1.
Fifty-three patients and 16 practitioners were included (Figure 1, Table 1).
Thirty-four (64%) patients were currently using a pMDI, 28 (53%) a DPI, and 8 (15%) an SMI. Seventeen (32%) were using multiple types of inhalers. There were no differences in types of inhalers between diseases. Most patients were “somewhat satisfied” or “satisfied” with their inhalers. There was little difference in satisfaction between those only using pMDIs (75%) versus DPIs (89%).
Factors influencing patients’ willingness to change inhaler type
The most important factor for patients changing an inhaler was symptom relief, with 47/53 (89%) of people rating this as “somewhat agree” or “strongly agree”. Most patients also considered ease of use 37/53 (70%), environmental impact 36/53(68%) and cost to the healthcare system 26/53 (49%) to be important, although symptom relief scored more highly than any of these (Figure 2).
Forty-four out of 53 (83%) of patients agreed or strongly agreed that global warming is an important issue and 35/53 (66%) considered the environmental impact of the healthcare that they receive. 26/53 (49%) of patients reported being aware that inhalers had some form of environmental impact.
Patients who consider the environmental impact of their healthcare were more likely to rank the environmental impact of inhalers as important than those who did not (p=0.040). There were no substantial or statistically significant differences between those concerned about global warming or aware of the environmental impact of inhalers, or between age, gender or disease. After information was provided on the environmental impact of inhalers, there was no appreciable difference in the willingness to consider the environment when choosing inhalers.
Factors influencing practitioners’ willingness to change inhaler type
All practitioners rated symptom relief and ease of use as having “some influence” or a “strong influence” in their decision of inhaler type. These were more important than both environmental impact and cost to the healthcare system (Figure 3).
Twelve out of 16 (75%) of practitioners believed global warming to be “very” or “extremely” important, but only 10 were aware of the difference in global warming potential between pMDIs and DPIs. After being given information about the environmental impact of the different types of inhalers, the number of practitioners who said that the environment would have either some influence or a strong influence on their prescribing increased from four (25%) to 12 (75%) (p=0.029). Practitioners’ concerns around DPIs included some patients not being able to use them due to their age or severity of disease, their ease of use, not wanting to change inhalers if patients had stable disease control on pMDIs, patient preference and a lack of familiarity with DPIs.
Discussion
We found that most patients and practitioners are willing to consider environmental impacts when choosing their inhalers once they had been made aware of the differences between inhaler types. Most patients expressed willingness to change their inhaler based on environmental considerations if their doctor recommended it.
As expected, the priorities for both patients and practitioners are ease of use and efficacy or symptom control. Most people who were unwilling to change their inhaler for environmental reasons indicated that they feared their disease would get out of control. However, DPIs have been shown to be as effective as pMDIs in controlling symptoms of both asthma and COPD, and improvements in quality of life and clinical outcomes have been observed when switching asthma and COPD patients from pMDIs to DPIs.[[7–10,31]] Furthermore, while the use of a short-acting beta-agonist pMDI with a spacer is currently the first-line intervention for acute severe bronchospasm, a review of 23 randomised trials found that the administration of short-acting beta-agonist through DPIs was as effective in treating acute severe asthma as pMDI therapy, both with and without a spacer.[[2–4,32]] Therefore, there may be scope for many patients to change to DPIs without compromising symptom relief and disease control. On the other hand, young children may not be suitable for DPI therapy due to the intricacies of their use and the lack of evidence in this age group.[[33]] All paediatricians in this study said that they prescribe pMDIs most frequently. Older children have been shown to use DPIs effectively and may be suitable for a trial of DPI therapy, but there are few studies of this.[[33]] Future reductions in the environmental impact of pMDI use in this age group could eventually be achieved through the use pMDI propellants with a lower global warming potential. These are currently being developed, but it will be several years before these become available.[[17,34]]
Most participants thought that global warming was an important issue, and two thirds considered the environmental impact of the healthcare they receive. However, only half of the participants were aware of the impact that inhalers have on the environment. Educating patients about this issue to increase awareness may influence future healthcare decisions to reduce global warming and environmental harm. However, we did not find that providing brief written information on the global warming potential of different inhalers made any immediate difference to patient attitudes to inhaler choices.
The wider environmental impact of inhaled treatment is less well understood. Although pMDIs have much greater overall global warming effects due to their hydrofluorocarbons propellants,[[7–10,24]] the full life cycle of DPIs may have greater impacts on fossil depletion, terrestrial acidification, freshwater and marine eutrophication and ecotoxicity, and the formation of photochemical oxidants due to the use of greater amounts of plastic and raw materials in their manufacture.[[24]] Future improvements in inhaler manufacture and reuse/recyclability of these inhalers may reduce these impacts.[[17]] However, none of these are as urgent as reducing the global warming potential of inhalers in the face of the current climate emergency. Another drawback is that many DPI inhaler devices are patented, making it more difficult to replace them with cheaper generic drugs, although most classes of drug now have several alternative preparations. As noted above, new propellants with a lower global warming potential may eventually make pMDIs an environmentally friendly and cost-effective choice.
Most hospital-based physicians and nurse specialists were aware of the difference in global warming potential between inhaler types, although providing written information did appear to increase the influence of environmental impacts of their inhaler choices. Ease of use and efficacy of the inhaler are the most important factors to consider when choosing inhalers. However, switching patients from pMDI- to DPI-based maintenance therapy reduces the annual inhaler carbon footprint by 55% without loss of asthma control.[[10]] Good disease control is important for environmental as well as clinical reasons: suboptimal disease control resulting in overuse of relieving medications may contribute to two thirds of greenhouse gas emissions from inhalers.[[35]]
To our knowledge, this is the first New Zealand study into environmental influences on inhaler prescribing and patient preferences regarding inhaler choices. Strengths include using both quantitative and qualitative techniques to gain a greater understanding of these factors. Interviewer bias was minimised by using standardised questionnaires, however, we did not validate the questionnaires and having multiple interviewers meant that it is possible that there were subtle differences in how participants were asked the questions. Social desirability bias may have resulted in a higher estimate of participants that consider the environment to be an issue compared to the actual population. Many patients were excluded for practical reasons (such as infection control or frailty), and we recruited only a small proportion of the practitioners that we approached. Other limitations of this study include an overrepresentation of inpatients, and the single-area setting (Southern), which led to a mostly older patient group with a higher proportion of NZ Europeans than the whole of New Zealand.[[36]] This is important because Māori and Pacific people experience a higher burden of respiratory disease. It would be informative to investigate these issues with different age and ethic patient groups and a larger sample of practitioners. We also need research on the efficacy of DPIs in young children and more data on their use in acute asthma exacerbations. In the meantime, more education on the environmental impact of inhalers may facilitate a change in prescribing habits for older children and adults.
Conclusion
With climate change having become a global emergency, it is important to explore how the healthcare sector can reduce its carbon footprint. This study indicates that many patients and practitioners are willing to consider changing to less environmentally damaging inhalers.
View Appendices.
Summary
Abstract
Aim
Inhalers are commonly used in the management of respiratory diseases. The propellants used in pressurised metered dose inhalers (pMDIs) are potent greenhouse gases and carry a substantial global warming potential. Dry powder inhalers (DPIs) are propellant-free alternatives that have fewer consequences on the environment, while being equally effective. In this study, we assessed patients’ and clinicians’ attitudes towards choosing inhalers that have a lesser environmental impact.
Method
Surveys of patients and practitioners were undertaken in primary and secondary care settings in Dunedin and Invercargill. Fifty-three patient and 16 practitioner responses were obtained.
Results
Sixty-four percent of patients were using pMDIs, while 53% were using DPIs. Sixty-nine percent of patients believed that the environment is an important consideration when switching inhalers. Sixty-three percent of practitioners were aware of the global warming potential of inhalers. Despite this, 56% of practitioners predominantly prescribe or recommend pMDIs. The 44% of practitioners who mostly prescribe DPIs were more comfortable doing so based on environmental impact alone.
Conclusion
Most respondents believe global warming is an important issue and would consider changing their inhaler to a more environmentally friendly type. Many people were not aware that pressurised metered dose inhalers have a substantial carbon footprint. Greater awareness of their environmental impacts may encourage the use of inhalers with lower global warming potential.
Author Information
Acknowledgements
Correspondence
Correspondence Email
Competing Interests
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26) Liew KL, Wilkinson A. P280 how do we choose inhalers? patient and physician perspectives on environmental, financial and ease-of-use factors. Thorax. 2017;72:A235-A237.
27) Stats NZ [Internet]. 2018 census ethnic groups dataset. 2020 [cited 2022 Aug 8]. Available from: https://www.stats.govt.nz/information-releases/2018-census-ethnic-groups-dataset/.
28) Stats NZ [Internet]. Statistical standard for gender, sex, and variations of sex characteristics. 2021 [cited 2022 Aug 8]. Available from: https://www.stats.govt.nz/methods/statistical-standard-for-gender-sex-and-variations-of-sex-characteristics.
29) Clinical Pharmacy Department [Internet]. Inhaler devices identification chart. Auckland: Counties Manukau Health; 2020 [cited 20 Oct 2022]. Available from: https://canvas.manukau.ac.nz/courses/48106.
30) National Institute for Health and care Excellence [Internet]. Patient decision aid: Inhalers for asthma. National Institute for Health and Care Excellence; 2020 [cited 30 Mar 2023]. Available from: https://www.nice.org.uk/guidance/ng80/resources/inhalers-for-asthma-patient-decision-aid-pdf-6727144573?UID=336247463202232945141.
31) Doyle C, Lennox L, Bell D. A systematic review of evidence on the links between patient experience and clinical safety and effectiveness. BMJ Open. 2013;3:e001570.
32) Selroos O. Dry-powder inhalers in acute asthma. Ther Deliv. 2014;5(1):69-81.
33) Hatter L, Bruce P, Beasley R. A breath of fresh AIR: Reducing the carbon footprint of asthma. J Med Econ. 2022 Jan-Dec;25(1):700-702.
34) AstraZeneca [Internet]. AstraZeneca progresses Ambition Zero Carbon programme with Honeywell partnership to develop next-generation respiratory inhalers. 2022 [cited 2022 Aug 12]. Available from: https://www.astrazeneca.com/media-centre/press-releases/2022/astrazeneca-progresses-ambition-zero-carbon-programme-with-honeywell-partnership-to-develop-next-generation-respiratory-inhalers.html.
35) Janson C, Maslova E, Wilkinson A, et al. The carbon footprint of respiratory treatments in Europe and Canada: an observational study from the carbon programme. Eur Respir J. 2022 Aug 10;60(2):2102760.
36) Environmental Health Intelligence New Zealand [Internet]. Ethnic profile. 2020 [cited 2022 Aug 10]. https://www.ehinz.ac.nz/indicators/population-vulnerability/ethnic-profile/.
Contact diana@nzma.org.nz
for the PDF of this article
Investigating attitudes and insights into the global warming impact of inhalers
Obstructive airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), affect over 800,000 people in New Zealand and are major contributors to morbidity and mortality. Inhaled medication is the mainstay of treatment for most patients.
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