Design: Cross-sectional survey.

Subjects: A total of 148 community-dwelling patients in Japan with a medical diagnosis of traumatic brain injury.

Methods: A postal questionnaire survey examined the relationships between individual's actual participation in community activities (working or attending school; undergoing rehabilitation at home or hospital; other) and productive activities evaluated by the CIQ in the community.

Results: Responses were received from 115 subjects (response rate 78%). Total CIQ scores and scores on the 3 subscales of the CIQ significantly differed among the 3 groups based on community participation. Total CIQ scores among individuals in the “working or attending school” group were significantly higher than for individuals in the “undergoing rehabilitation at home or hospital” and “other” groups. In addition, scores on the Productive Activity subscale of the CIQ were significantly higher among the “working or attending school” group than for the other 2 groups.

Conclusion: These results suggest that the CIQ has concurrent validity for patients with traumatic brain injury.