ABSTRACT
Objective: Multiple extra-pulmonary comorbidities contribute to difficult asthma, but their diagnosis can be challenging and time consuming. Previous data on comorbidity detection have focused on clinical assessment, which may miss certain conditions. We aimed to locate relevant validated screening questionnaires to identify extra-pulmonary comorbidities that contribute to difficult asthma, and evaluate their performance during a difficult asthma evaluation. Methods: MEDLINE was searched to identify key extra-pulmonary comorbidities that contribute to difficult asthma. Screening questionnaires were chosen based on ease of use, presence of a cut-off score, and adequate validation to help systematically identify comorbidities. In a consecutive series of 86 patients referred for systematic evaluation of difficult asthma, questionnaires were administered prior to clinical consultation. Results: Six difficult asthma comorbidities and corresponding screening questionnaires were found: sinonasal disease (allergic rhinitis and chronic rhinosinusitis), vocal cord dysfunction, dysfunctional breathing, obstructive sleep apnea, anxiety and depression, and gastro-oesophageal reflux disease. When the questionnaires were added to the referring clinician's impression, the detection of all six comorbidities was significantly enhanced. The average time for questionnaire administration was approximately 40 minutes. Conclusions: The use of validated screening questionnaires heightens detection of comorbidities in difficult asthma. The availability of data from a battery of questionnaires prior to consultation can save time and allow clinicians to systematically assess difficult asthma patients and to focus on areas of particular concern. Such an approach would ensure that all contributing comorbidities have been addressed before significant treatment escalation is considered.
Acknowledgments
We would like to thank the nursing staff for their involvement in the difficult asthma clinic protocol.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.
Author contributions
All authors have been involved in the setup of the difficult asthma service as well as patient management. All authors read and approved the final manuscript. No funding was provided for this study.