Psychometric Characteristics of the Child Occupational Self Assessment (COSA), part one: an initial examination of psychometric properties.

Pediatric occupational therapists have a unique opportunity to foster self-determination by involving young clients in assessment and intervention planning. Self-assessment is an appropriate way to support client-centered practice and self-determination. This study is the first in a series of two studies that examined the psychometric properties of the Child Occupational Self Assessment (COSA), a self-report tool based on the Model of Human Occupation. The COSA comprises 24 statements, which the child rates in terms of personal competence and importance. The Rasch Rating Scale Model was used to evaluate the measurement properties of the Competence and Values scales that result from these self-ratings. Analysis indicated that the items worked well together to constitute measures of occupational competence and values. However, the instrument was not sufficiently sensitive to discriminate among respondents. Future recommendations are made to expand the rating scales in order to increase client discrimination so that the COSA can also be used as an outcome assessment. The results provide initial evidence that the COSA can be used as meaningful and reliable client directed assessment tool.