AbstractIntroduction and objectives
Comorbid anxiety disorders are common among patients with COPD, affecting up to half of all patients. Comorbid anxiety may be a significant factor in predicting quality of life, yet recognition and management of anxiety among this patient group is poor. Screening and measuring symptoms of anxiety can be challenging due to the overlap of physical symptoms and the lack of a validated disease-specific tool. The aim of this study was to develop a novel non-somatic scale (Anxiety Inventory for Respiratory disease (AIR)) to screen and measure anxiety in patients with COPD.Methods
This study utilised a multi-method approach to scale development incorporating both qualitative and quantitative methods. An item pool was developed using in-depth interviews with COPD patients who exhibited symptoms of anxiety (n=14), and the analysis of existing anxiety scales. Item wording, content and user-friendliness were checked by an expert reference group (ERG) that included clinicians and patients. This item pool was tested on a group of COPD patients (n=82). The Likert-type scale has four consistent responses to statements (Not at all, Occasionally, Frequently, Almost all of the time) that are scored from 0 to 3. Item and factor analysis were carried out to aid in item reduction and to explore the factor structure.Results
Sixteen items were selected for inclusion following development and approval from the ERG. Items were retained based on item-to-total correlation analysis and α-if-item-deleted analysis. One item was discarded as it had a corrected-item-to-total correlation of <0.55. Exploratory principal component factor analysis was performed and three further items were removed due to low communalities (<0.50). Secondary analysis indicated a single factor solution accounting for 66.67% of total variance with a mean communality of 0.67. Abstract S93 table 1 shows the factor loadings for the final items. The 12-item scale had a mean total score of 13.55 (SD=9.41, range=0–36), and a Cronbach's α of 0.95.Conclusions
The AIR is a short self-report non-somatic anxiety scale with a clear uni-dimensional factor solution and high internal consistency. Additional studies are warranted to further explore the scale's psychometric properties and to establish its ability to screen for clinical anxiety disorders.