Article Text

Download PDFPDF
P186 Carbon footprint analysis of the salford lung study (asthma): A SusQI analysis
  1. FJN Hunt,
  2. A Wilkinson
  1. East and North Herts NHS Trust, Stevenage, UK


The UK is aiming for net zero carbon emissions by 2050 and the NHS makes up roughly 5% of the total carbon footprint. Inhaler therapies have high potential for carbon savings. Metered dose inhalers (MDI) have a very high carbon footprint as they contain hydrofluoroalkane propellants which are potent greenhouse gases. Dry powder inhalers (DPI), have a much smaller footprint and make up only 30% of inhaler usage in the UK (far lower than other European countries).

The Salford lung study (SLS) was a randomised control trial assessing a single combined DPI, Fluticasone Furoate/Vilanterol (FF/VI), against usual care in asthma management across a 12-month period.1Patient health outcomes, cost-effectiveness and employment outcomes have previously been reported. The Sustainable quality improvement (SusQI) framework assesses projects using a ‘triple bottom line’ of environmental, social and economic costs and is used to motivate healthcare workers to bring about positive change.2 We used SusQI methodology and NHS Sustainable development data to calculate the carbon footprint of the two treatment arms. Additionally, the carbon footprint of healthcare visits and hospital stays were calculated.

We calculated a saving of 141 kg CO2e per patient per year in the FF/VI arm. Prior to randomisation, 70% of patients were using MDI maintenance therapy. The majority of the greenhouse gas savings (129 kg CO2e) derived from switching from MDI to DPI maintenance treatment. The carbon footprint of salbutamol therapy was slightly lower in the treatment arm; 156 kg in FF/VI group vs 137 kg CO2e in the usual care arm. Usual care and FF/VI had little difference in carbon footprint of healthcare visits, 73 kg and 79 kg CO2e respectively.

Patients randomised to FF/VI had a significant saving in their carbon footprint compared to standard care, alongside improvements in clinical outcomes. Future clinical trials should consider including not just patients’ health outcomes, but also the triple bottom line of the environmental, social and financial costs.

Abstract P186 Figure 1

Chart showing the mean carbon footprint per person of the three measured outcomes and as a total


  1. Woodcock, et al. The Salford Lung Study protocol: a pragmatic, randomised phase III real-world effectiveness trial in asthma. BMC Pulmonary Medicine 2015;15(1).

  2. Mortimer, Wilkinson, et al. Sustainability in quality improvement: redefining value. Future Healthcare Journal 2018;5(2):88–93.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.