Translation and assessment of psychometric properties of the French version of the Adult Developmental Coordination Disorder/Dyspraxia Checklist (ADC)

Developmental Coordination Disorder (DCD) is a neurodevelopmental disorder that emerges during childhood, affecting approximately 5-8% of school-age children. Although it often persists into adulthood, there is a lack of standardized and validated tools for assessing DCD in adults in France. The Adult Developmental Coordination Disorder/Dyspraxia Checklist (ADC) is the most widely used questionnaire in DCD studies with adults and has been adapted in several countries. This study aimed to translate the ADC into French and to evaluate its psychometric properties. The questionnaire was translated following literature recommendations. A total of 209 participants aged 18-58 years were included (138 females, mean age: 24.49 ± 7.87 years, mean laterality quotient: 71.41% ± 45.85%), including 13 with a reported diagnosis of DCD or probable DCD. The psychometric properties related to evidence of validity and reliability were then assessed. The test of the questionnaire structure led to a 28-item modified version instead of the 40-item original one. Analyses of the other psychometric properties provided initial evidence based on test content, internal structure, relations with validated motor tests, and sensitivity to DCD. The ADC also showed acceptable to excellent internal consistency and test-retest reliability. Preliminary French thresholds and minimal detectable change values (e.g., following an intervention) were calculated. This article represents a first step in the validation process of the French ADC, in line with French and European recommendations on DCD. It also contributes to harmonizing diagnostic tools and supporting international research on adults with DCD.