Comorbid “treatable traits” in difficult asthma: Current evidence and clinical evaluation

T. R. Tay, M. Hew

Research output: Contribution to journalReview ArticleResearchpeer-review

71 Citations (Scopus)


The care of patients with difficult-to-control asthma (“difficult asthma”) is challenging and costly. Despite high-intensity asthma treatment, these patients experience poor asthma control and face the greatest risk of asthma morbidity and mortality. Poor asthma control is often driven by severe asthma biology, which has appropriately been the focus of intense research and phenotype-driven therapies. However, it is increasingly apparent that extra-pulmonary comorbidities also contribute substantially to poor asthma control and a heightened disease burden. These comorbidities have been proposed as “treatable traits” in chronic airways disease, adding impetus to their evaluation and management in difficult asthma. In this review, eight major asthma-related comorbidities are discussed: rhinitis, chronic rhinosinusitis, gastroesophageal reflux, obstructive sleep apnoea, vocal cord dysfunction, obesity, dysfunctional breathing and anxiety/depression. We describe the prevalence, impact and treatment effects of these comorbidities in the difficult asthma population, emphasizing gaps in the current literature. We examine the associations between individual comorbidities and highlight the potential for comorbidity clusters to exert combined effects on asthma outcomes. We conclude by outlining a pragmatic clinical approach to assess comorbidities in difficult asthma.

Original languageEnglish
Pages (from-to)1369-1382
Number of pages14
Issue number7
Publication statusPublished - Jul 2018


  • comorbidity
  • diagnosis
  • difficult asthma
  • severe asthma
  • treatment

Cite this