Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention. https://ginasthma.org/wp-content/uploads/2023/05/GINA-2023-Full-Report-2023-WMS.pdf (2023).

Global Initiative for Chronic Obstructive Lung Disease. Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease (2023 Report). https://goldcopd.org/wp-content/uploads/2023/01/GOLD-2023-ver-1.2-7Jan2023_WMV.pdf (2023).

McDonald, V. M. & Gibson, P. G. Treatable traits and their application in high-, middle- and low-income countries. Respirology 24, 942–943 (2019).

Article  PubMed  Google Scholar 

Agusti, A. et al. Treatable traits: toward precision medicine of chronic airway diseases. Eur. Respir. J. 47, 410–419 (2016).

Article  PubMed  Google Scholar 

Pavord, I. D. et al. After asthma: redefining airways diseases. Lancet 391, 350–400 (2018).

Article  PubMed  Google Scholar 

Shaw, D. E., Gaynor, C. M. & Fogarty, A. W. Changes in asthma mortality in England and Wales since 2001. Thorax 74, 1174–1175, https://doi.org/10.1136/thoraxjnl-2019-213350 (2019).

Article  PubMed  Google Scholar 

Shaw, D. E. et al. Balancing the needs of the many and the few: where next for adult asthma guidelines? Lancet Respir. Med. 9, 786–794 (2021).

Beasley, R. et al. Optimal asthma control: time for a new target. Am. J. Respir. Crit. Care Med. 201, 1480–1487 (2020).

Article  PubMed  Google Scholar 

Bateman, E. D. et al. Can guideline-defined asthma control be achieved? The Gaining Optimal Asthma ControL study. Am. J. Respir. Crit. Care Med. 170, 836–844 (2004).

Beasley, R. et al. Inhaled corticosteroid therapy in adult asthma. Time for a new therapeutic dose terminology. Am. J. Respir. Crit. Care Med. 199, 1471–1477 (2019).

Fabbri, L. M. et al. COPD and multimorbidity: recognising and addressing a syndemic occurrence. Lancet Respir. Med. https://doi.org/10.1016/s2213-2600(23)00261-8 (2023).

Agusti, A., Gibson, P. G. & McDonald, V. M. Treatable traits in airway disease: from theory to practice. J. Allergy Clin. Immunol. Pract. 11, 713–723 (2023).

Article  PubMed  Google Scholar 

Kirkland, S. W., Cross, E., Campbell, S., Villa-Roel, C. & Rowe, B. H. Intramuscular versus oral corticosteroids to reduce relapses following discharge from the emergency department for acute asthma. Cochrane Database Syst. Rev. 6, CD012629 (2018).

PubMed  Google Scholar 

Rowe, B. H., Spooner, C. H., Ducharme, F. M., Bretzlaff, J. A. & Bota, G. W. Corticosteroids for preventing relapse following acute exacerbations of asthma. Cochrane Database Syst. Rev. 18, CD000195 (2007).

Google Scholar 

Bloechliger, M. et al. Adverse events profile of oral corticosteroids among asthma patients in the UK: cohort study with a nested case-control analysis. Respir. Res. 19, 75 (2018).

Price, D. B. et al. Adverse outcomes from initiation of systemic corticosteroids for asthma: long-term observational study. J. Asthma Allergy 11, 193–204 (2018).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Barry, L. E., Sweeney, J., O’Neill, C., Price, D. & Heaney, L. G. The cost of systemic corticosteroid-induced morbidity in severe asthma: a health economic analysis. Respir. Res. 18, 129 (2017).

Blakey, J. et al. Oral corticosteroids stewardship for asthma in adults and adolescents: a position paper from the Thoracic Society of Australia and New Zealand. Respirology 26, 1112–1130 https://doi.org/10.1111/resp.14147.

Sweeney, J. et al. Comorbidity in severe asthma requiring systemic corticosteroid therapy: cross-sectional data from the Optimum Patient Care Research Database and the British Thoracic Difficult Asthma Registry. Thorax 71, 339–346 (2016).

Article  PubMed  Google Scholar 

Seys, S. F. et al. Cluster analysis of sputum cytokine-high profiles reveals diversity in T(h)2-high asthma patients. Respir. Res. 18, 39 (2017).

Article  PubMed  PubMed Central  Google Scholar 

Peters, M. C. et al. Measures of gene expression in sputum cells can identify TH2-high and TH2-low subtypes of asthma. J. Allergy Clin. Immunol. 133, 388–394 (2014).

Article  CAS  PubMed  Google Scholar 

George, L. & Brightling, C. E. Eosinophilic airway inflammation: role in asthma and chronic obstructive pulmonary disease. Ther. Adv. Chronic Dis. 7, 34–51 (2016).

Article  CAS  PubMed  PubMed Central  Google Scholar 

Heaney, L. G. et al. Eosinophilic and noneosinophilic asthma: an expert consensus framework to characterize phenotypes in a global real-life severe asthma cohort. Chest 160, 814–830 (2021).

Article  CAS  PubMed  Google Scholar 

David, B., Bafadhel, M., Koenderman, L. & De Soyza, A. Eosinophilic inflammation in COPD: from an inflammatory marker to a treatable trait. Thorax 76, 188 (2021).

Article  PubMed  Google Scholar 

Hastie, A. T. et al. Association of sputum and blood eosinophil concentrations with clinical measures of COPD severity: an analysis of the SPIROMICS cohort. Lancet Respir. Med. 5, 956–967 (2017).

Article  PubMed  PubMed Central  Google Scholar 

Wagener, A. H. et al. External validation of blood eosinophils, FE(NO) and serum periostin as surrogates for sputum eosinophils in asthma. Thorax 70, 115–120 (2015).

Article  CAS  PubMed  Google Scholar 

Yancey, S. W. et al. Biomarkers for severe eosinophilic asthma. J. Allergy Clin. Immunol. 140, 1509–1518 (2017).

Article  CAS  PubMed  Google Scholar 

Price, D. et al. Using fractional exhaled nitric oxide (FeNO) to diagnose steroid-responsive disease and guide asthma management in routine care. Clin. Transl. Allergy 3, 37 (2013).

Article  PubMed  PubMed Central  Google Scholar 

British Thoracic Society and Scottish Intercollegiate Guidelines Network. British Guideline on the Management of Asthma. https://www.brit-thoracic.org.uk/quality-improvement/guidelines/asthma/ (2019).

Louis, R. et al. European Respiratory Society guidelines for the diagnosis of asthma in adults. Eur. Respir. J 15, 21015852101585, https://www.ncbi.nlm.nih.gov/pubmed/35169025 (2022).

Korevaar, D. A. et al. Effectiveness of FeNO-guided treatment in adult asthma patients: a systematic review and meta-analysis. Clin. Exp. Allergy 53, 798–808 (2023).

Article  CAS  PubMed  Google Scholar 

Boddy, C. E. et al. Clinical outcomes in people with difficult-to-control asthma using electronic monitoring to support medication adherence. J. Allergy Clin. Immunol. Pract. 9, 1529–1538.e1522 (2021).

Article  PubMed  Google Scholar 

Faruqi, S. et al. Suppression of F (ENO) with observed inhaled corticosteroid therapy in severe asthma: is it a useful test in clinical practice? ERJ Open Res. 5, https://doi.org/10.1183/23120541.00123-2019 (2019).

Butler, C. A. et al. Utility of fractional exhaled nitric oxide suppression as a prediction tool for progression to biologic therapy. ERJ Open Res. 00273–02021. https://doi.org/10.1183/23120541.00273-2021 (2021).

Barry, L. E., O’Neill, C., Butler, C., Chaudhuri, R. & Heaney, L. G. Cost-effectiveness of fractional exhaled nitric oxide suppression testing as an adherence screening tool among patients with difficult-to-control asthma. J. Allergy Clin. Immunol. Pract. 11, 1796–1804.e1793, https://doi.org/10.1016/j.jaip.2023.03.008 (2023).

Article  CAS  PubMed  Google Scholar 

University of Southampton. Research project: DEFINE: Development and Evaluation of a FeNO-Guided Asthma Management Intervention in Primary Care. https://www.southampton.ac.uk/research/projects/m-thomas-nihr-pgfar-via-oxford-development-evaluation-of-an-online-feno-guided (2022).

Singh, D. et al. Blood eosinophils and chronic obstructive pulmonary disease: a global initiative for chronic obstructive lung disease science committee 2022 review. Am. J. Respir. Crit. Care Med. 206, 17–24 (2022).

Article  CAS  PubMed  Google Scholar 

Lee, L. A. et al. Efficacy and safety of once-daily single-inhaler triple therapy (FF/UMEC/VI) versus FF/VI in patients with inadequately controlled asthma (CAPTAIN): a double-blind, randomised, phase 3A trial. Lancet Respir. Med. 9, 69–84 (2021).

Article  CAS  PubMed  Google Scholar 

Demarche, S. F. et al. Effectiveness of inhaled corticosteroids in real life on clinical outcomes, sputum cells and systemic inflammation in asthmatics: a retrospective cohort study in a secondary care centre. BMJ Open 7, e018186 (2017).

Article  PubMed  PubMed Central  Google Scholar 

Price, D. B. et al. Blood eosinophil count and prospective annual asthma disease burden: a UK cohort study. Lancet Respir. Med. 3, 849–858 (2015).

Article  PubMed  Google Scholar 

Couillard, S. et al. Derivation of a prototype asthma attack risk scale centred on blood eosinophils and exhaled nitric oxide. Thorax 77, 199–202 (2021).

Article  PubMed  Google Scholar 

McDonald, V. M., Higgins, I. & Gibson, P. G. Insight into older peoples’ healthcare experiences with managing COPD, asthma, and asthma-COPD overlap. J. Asthma 50, 497–504 (2013).

Article  PubMed  Google Scholar 

Reddel, H. K. et al. Heterogeneity within and between physician-diagnosed asthma and/or COPD: NOVELTY cohort. Eur. Respir. J. 58, https://doi.org/10.1183/13993003.03927-2020 (2021).

Jaakkola, M. S., Hyrkäs-Palmu, H. & Jaakkola, J. J. K. Residential exposure to dampness is related to reduced level of asthma control among adults. Int. J. Environ. Res. Public Health 19, https://doi.org/10.3390/ijerph191811338 (2022).

Simpson, A. J. et al. Treatable traits in the European U-BIOPRED adult asthma cohorts. Allergy 74, 406–411 (2019).