Development and Validation of the Functional Difficulties Questionnaire for Assessing Developmental Coordination Disorder in Adults.

Abstract

PURPOSE: The purpose of this study was to describe the development and preliminary psychometric evaluation of the Functional Difficulties Questionnaire (FDQ-9), an instrument designed to aid clinicians in the assessment of developmental coordination disorder (DCD) in adults. RELEVANCE: There are currently no tools to assess DCD in adults with musculoskeletal pain. DCD is a neurodevelopmental disorder characterized by functional motor impairments described in childhood that, for some, persist into adulthood. Skill impairments in those with DCD include impaired perception and biomechanical dysfunction. METHODS: The questionnaire was developed utilizing existing questionnaires, the Diagnostic and Statistical Manual for the Diagnosis of Mental Disorders (DSM-IV) criteria for the diagnosis of DCD, International Classification of Diseases (ICD-10), and International Classification of Functioning, Disability and Health (ICF). An initial 13-item pool was reviewed by an expert panel for face and content validity. This resulted in a 9-item questionnaire that was piloted on 3 groups (n = 257): (1) individuals with joint hypermobility syndrome, (2) convenience samples from a commercial company, and (3) staff and students of a university. Exploratory factor analysis was employed to assess the underlying factor structure. Aspects of validity and reliability were assessed. RESULTS: Factor analysis using principal-axis factoring with oblimin rotation yielded 2 factors relating to fine and gross motor function. Overall internal reliability was high (á = .81). Preliminary findings suggested satisfactory construct validity and test-retest reliability (ICC = 0.96; 95% CI: 0.92, 0.98). CONCLUSIONS: Psychometric properties of this questionnaire appear promising, but further research is required to evaluate the validity of the questionnaire in new samples and audit its application in clinical practice. IMPLICATIONS: This questionnaire has the potential to aid clinicians in their assessment of DCD and functional impairments in adults and therefore contribute to improved care planning.