The Fear of Asthma Symptoms Scale and the Asthma Behavior Checklist: preliminary validity of two novel patient reported outcome measures

Objective: The aim of this study was to investigate the preliminary validity of two novel scales, the Fear of Asthma Symptoms scale (FAS) and the Asthma Behavior Checklist (ABC). Methods: Using cross-sectional design, data was collected online from 188 adult participants (Age 18-71 years) with a diagnosis of asthma and self-reported anxiety related to asthma, recruited through social media. Confirmatory factor analysis, internal consistency and test-retest reliability were ascertained to address validity.Results: The confirmatory factor analysis demonstrated convergent validity for both the FAS (average variance extracted; AVE=.57) and the item-reduced ABC-8 (AVE=.61) as well as divergent validity for both scales. Both scales demonstrated high internal consistency (FAS: α = 0.94; ABC-8: α = 0.92). Test-retest reliability assessed after 1 week was good (FAS: r=.85; ABC-8: r=.88).Conclusions: We observed promising psychometric properties of the FAS and the ABC-8. The two novel scales could be useful to identify excessive fear and avoidance in patients with asthma and to investigate putative mechanisms in clinical research on anxiety related to asthma. Further evaluation of psychometric properties in independent samples are needed.