Thorax 66:910-917 doi:10.1136/thx.2010.153643
  • Review

Diagnosis and definition of severe refractory asthma: an international consensus statement from the Innovative Medicine Initiative (IMI)

  1. on behalf of the members of the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcome (U-BIOPRED) Consortium, Consensus Generation9
  1. 1Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
  2. 2GlaxoSmithKline, Stevenage, UK
  3. 3Clinical Trials and Evaluation Unit, Imperial College London, London, UK
  4. 4Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, UK
  5. 5Airways Disease, National Heart and Lung Institute, Imperial College, London, UK
  6. 6Asthma UK, London, UK
  7. 7BioSci Consulting, Maasmechelen, Belgium
  8. 8European Federation of Pharmaceutical Industries and Associations (EFPIA), EFPIA Headquarters, Brussels, Belgium
  9. 9European Union (EU) Innovative Medicines Initiative (IMI) Program Understanding Severe Asthma, Consortium Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED)
  1. Correspondence to Professor Dr Elisabeth H Bel, Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; e.h.bel{at}
  1. Contributors All authors contributed actively to the consensus meeting, revised and changed the manuscript critically and approved the version published. EHB chaired the consensus meeting, developed the framework for the review and wrote the first version of the manuscript. AS, LF, AB, KFC, JV, AHW, SSW, PJS and CC assisted in writing the manuscript and revised the subsequent versions. All participants in the consensus meeting and the U-BIOPRED consortium had the opportunity to review and revise the pre-definitive version of the manuscript. All co-authors were core members of U-BIOPRED work package “Consensus Generation”.

  • Received 17 October 2010
  • Accepted 20 October 2010
  • Published Online First 23 November 2010


Patients with severe refractory asthma pose a major healthcare problem. Over the last decade it has become increasingly clear that, for the development of new targeted therapies, there is an urgent need for further characterisation and classification of these patients. The Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) consortium is a pan-European public-private collaboration funded by the European Commission Innovative Medicines Initiative of the European Union. U-BIOPRED aims to subphenotype patients with severe refractory asthma by using an innovative systems biology approach. This paper presents the U-BIOPRED international consensus on the definition and diagnosis of severe asthma, aligning the latest concepts in adults as well as in children. The consensus is based on existing recommendations up to 2010 and will be used for the selection of patients for the upcoming U-BIOPRED study. It includes the differentiation between ‘problematic’, ‘difficult’ and ‘severe refractory’ asthma, and provides a systematic algorithmic approach to the evaluation of patients presenting with chronic severe asthma symptoms for use in clinical research and specialised care.


  • List of contributors at the U-BIOPRED International Consensus Definition and Diagnosis of Severe Asthma: Bel EH, Bergeron C, Bisgaard H, Bleecker E, Boulet L-P, Bousquet J, Brightling CE, Bush A, Castro M, Chanez P, Chung KF, Compton CH, Cookson W, de Boer WI, Djukanovic R, Fleming L, Gaga M, Hedlin G, Howarth PH, Ivanoff N, Kiley J, Larsson LG, Menzies-Gow A, Meyers DA, Myles D, Nething K, O'Byrne PM, Palkonen S, Polosa R, Purkins L, Rohou S, Serdrevic D, Sousa A, Sterk PJ, Ventresca G, Versnel J, Wagener AK, Wagers SS, Wenzel SE.

  • Funding This report was supported by grants from the European Commission Innovative Medicine Initiative Understanding Severe Asthma, IMI_Call_2008_1_12; final protocol available at

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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