Development of the Avoidance Daily Activities Photo Scale for Patients With Shoulder Pain.

Objectives: The purpose of this study was to develop the Avoidance of Daily Activities Photo Scale (ADAP Shoulder Scale) to measure shoulder pain-related avoidance behavior in patients with shoulder pain and evaluate and report the structural validity and internal consistency of the scale.

Methods: Potential daily activities involving the shoulder were selected from the activities and participation domain of the International Classification of Functioning, Disability and Health. The selected activities were presented to an expert panel, health care professionals, and patients with shoulder pain with the question "How much do you think it is important to ask patients with shoulder pain about this activity?" Activities attaining a content validity index (CVI) ≥ 0.8 were represented using a digitally colored photograph. Activity photographs were evaluated by health care professionals and patients with shoulder pain. Photographs with a CVI ≥ 0.8 were included in the scale. To evaluate structural validity and internal consistency of the scale, exploratory factor analysis was performed to determine the presence of any scale domain. Cronbach alpha was calculated to indicate the internal consistency of each domain.

Results: Of the 107 preselected activities, 21 attained a CVI ≥ 0.8. Eighteen photographs (CVI ≥ 0.8) were included in the scale after being analyzed by 120 health care professionals and 50 patients with shoulder pain. Exploratory factor analysis (N = 156) showed that the ADAP Shoulder Scale consists of 3 domains: free movement, high effort, and self-care. The internal consistencies of the domains were 0.92, 0.89, and 0.92, respectively.

Conclusion: The ADAP Shoulder Scale included 15 photographs distributed in 3 domains. All domains had a high internal consistency. The scale is easily applicable, well understood, and relevant for shoulder pain.

Impact: The ADAP Shoulder Scale can be used to rate shoulder pain-related avoidance behaviors.