Rasch Analysis of the Assessment of Quality of Activities (A-QOA), an Observational Tool for ClientsWith Dementia

Abstract

Importance: The Assessment of Quality of Activities (A-QOA) is an observation-based tool for assessing the strength of engagement in an activity by the person performing it in a natural context. By quantifying the quality of engagement, the A-QOA can help occupational therapy practitioners be better able to select meaningful activities and more clearly understand the effectiveness of various choices. Objective: To examine use of the A-QOA as a valid unidimensional scale and to clarify preliminary results on its internal scale validity and item reliability using the Rasch model. Participants: One hundred thirty-one participants with dementia performing 262 activities. Outcomes and Measures: We used the Rasch model to clarify the psychometric properties of A-QOA's measurement quality. Results: Rasch analysis revealed that 21 of the 25 items reached an acceptable level of fit, and 4 did not. After eliminating the 4 misfitting items, the resulting A-QOA was determined to have both acceptable internal scale validity and item separation reliability, which are fundamental psychometric properties of a clinical observational instrument. Conclusions and Relevance: The A-QOA can be used to quantitatively assess the strength of engagement in an activity by the person performing it by using the observational method.