Development and Validation of the Occupational Self-Assessment-Short Form (OSA-SF)

Importance: The Occupational Self-Assessment, Version 2.2 (OSA 2.2), is a client-centered measure of clients' perceived occupational competence and value. The OSA 2.2 has previously demonstrated good structural validity and internal consistency; however, the administration length could deter therapists from using this assessment in acute care and acute inpatient rehabilitation. Objective: To evaluate reliability and validity of the OSA 2.2 in acute care and acute inpatient rehabilitation and to develop and validate the OSA-Short Form (OSA-SF). Design: We performed a descriptive psychometric analysis using the Rasch analytic approach. Setting: The data were collected in acute care and acute inpatient rehabilitation. Participants: Our convenience sample consisted of 86 patients in acute care and acute inpatient rehabilitation. Outcomes and Measures: Participants rated their perceived occupational competence and value by completing the OSA 2.2. Results: We examined psychometric properties of the OSA 2.2 and OSA-SF using a partial credit Rasch model. The 21-item OSA 2.2 was reduced to a 12-item OSA-SF through iterative removal of items on the basis of item-misfit statistics. The OSA-SF demonstrated adequate rating scale functioning, dimensionality, item and person goodness of fit, item targeting, item hierarchies, and item and person separation. Conclusions and Relevance: Findings indicate that the OSA-SF is a valid and reliable measure that can guide client-centered goal setting and intervention planning for adults receiving acute care and acute inpatient rehabilitation. What This Article Adds: The OSA 2.2 and the OSA-SF offer a client-centered approach to evaluating patients' self-reported ability and ratings of the importance of performing everyday occupations. These assessments can guide client-centered goal setting in acute care and acute inpatient rehabilitation.