The reproducibility and validity of the Canadian Occupational Performance Measure in parents of children with disabilities

Objective: To study the reproducibility (inter-rater agreement), the construct and criterion validity of the Canadian Occupational Performance Measure (COPM) in the parents of children with disabilities. Design: The COPM was administered twice by two different occupational therapists. The inter-rater agreement of the content of the prioritized problems was explored. Data analysis of the reproducibility of the scores was based on the Bland and Altman method. Measures used: The construct validity was studied by comparing the results of the COPM with the Pediatric Evaluation of Disability Inventory, and a quality of life questionnaire. The criterion validity was verified with an open-ended question. Setting: Occupational therapy departments of a university hospital and three rehabilitation institutes. Subjects: One hundred and twenty-nine consecutive parents of children referred for occupational therapy. Results: Data were obtained for 80 children with a mean age of 3.7 years (range 1-7.5). Of the prioritized problems identified in the first interview, 80% were also prioritized in the second interview. The limits of agreement were -2.4 to +2.3 for the mean performance score and -2.3 to +2.6 for the mean satisfaction score. Assumptions about the construct and criterion validity were confirmed. Conclusions: The inter-rater agreement of the prioritized problems is good enough for client-centred occupational therapy. The reproducibility of the performance and satisfaction scores is moderate. The results support the construct and criterion validity. The COPM identifies many child-unique problems that are not assessed with existing standardized measurement instruments or with a simple open-ended question.