Abstract
INTRODUCTION: There is an established association between asthma and anxiety. The overlap between asthma symptoms and symptoms of anxiety may cause individuals to overestimate their asthma severity and restrict their daily activities leading to a low quality of life. There is currently weak evidence for treatments targeting anxiety related to asthma, but cognitive-behavioural therapy (CBT) has shown some promising but mixed results. The current randomised controlled trial will investigate if exposure-based internet-delivered CBT (Internet-CBT) is more effective than treatment as usual+medical education (TAU+ME) to relieve symptoms of anxiety and asthma control. METHODS AND ANALYSIS: 90 participants will be randomised 1:1 to 8 weeks of Internet-CBT or TAU+ME. The primary outcome, the patient-reported Catastrophising Asthma Scale, will be analysed from baseline to the primary endpoint at 16 weeks using hierarchical linear mixed model of the slope over time. Secondary outcomes, such as asthma control, quality of life and forced expiratory volume in 1 s, will be analysed correspondingly. ETHICS AND DISSEMINATION: All participants will be informed about the study and leave their consent before study entry. All results will be analysed at group level and reported through publication in a peer-reviewed scientific journal within the field. The study received ethical approval by the Swedish Ethical Review Authority in January 2020 (ID: 2019-05985; 2022-01117-02). TRIAL REGISTRATION NUMBER: Registered at ClinicalTrials.gov (ID: NCT04230369).