Background: The Canadian Occupational Performance Measure (COPM) is among the most well-known assessments in occupational therapy. However, neither the assessment itself nor the scale, have ever been tested to its cultural sensitivity for the use in Austrian population. The aim of this study was to test the scale in the Austrian population, compare it to better known scales in Austria such as the VAS and the Austrian school grading system and see if a cultural adaption has to be made.
Method: The data for the study was collected with the help of an online questionnaire. 194 participants self-assessed their performance on four different activities of daily life using all three scales. A Rasch analysis has been done to evaluate the received values.
Results: Results showed a high correlation among all three scales and all four items with correlation values varying between 0.75 and 0.95. Nevertheless, allocation of the scores has been often poor. Additionally, uniform differential item functioning (DIF) between male and female participants and in the age has been seen. Furthermore, the category probability curves presented high variances on where the thresholds overlapped.
Conclusion: The study provides good support that the COPM scale seems to be less culturally dependent than anticipated. However, disordered thresholds and poorly allocated scores necessitate the development of clear definitions and detailed descriptions for the units of the scale. Furthermore, measurement invariances in gender and age have to be kept in mind for practice in order to make the right inferences of the scores.