Development and Validation of the Korean Version of the Rett Syndrome Behavioral Questionnaire

Research Objectives: To develop and validate the Korean Version of the Rett Syndrome Behavioral Questionnaire (RSBQ).

Design: We translated the original RSBQ into Korean and developed the K-RSBQ. We recruited RTT caregivers who attended the Korean Association of Parents for Rett Syndrome and provided consent for participation. We asked the primary caregivers to administer the online questionnaire, including the K-RSBQ and Childhood Autism Rating Scale (CARS). One week after the main survey, we asked the main caregivers of the children to answer the RSBQ again to test inter-rater reliability.

Setting: Korean Association of Parents for Rett Syndrome through tertiary hospital

Participants: Between September and December 2023, this cross-sectional survey study enrolled caregivers of RTT who joined the Korean Association of Parents for Rett Syndrome.

Interventions: The main caregivers were asked to administer the online questionnaire. If there was a close caregiver other than the main caregiver, an online survey was conducted with each of them to test the inter-rater reliability. One week after the main survey, the main caregivers were asked to answer the K-RSBQ again to test the inter-rater reliability.

Main Outcome Measures: The RSBQ is a caregiver-completed scale, assessing various neurological and behavioral RTT symptoms, initially developed as a diagnostic tool to differentiate children with RTT from those with severe intellectual disability.

Results: K-RSBQ was administered by 66 main RTT caregivers. The average and median age of the children with RTT were 12.89 (SD 0.85) and 11.95 (IQR 7.56– 16.54) years, respectively. The K-RSBQ displayed high internal consistency with a Cronbach’s alpha of 0.912 for the total score. The intraclass correlations between the first and second completion of the K-RSBQ for the total score and that between the main and other caregivers were 0.912 and 0.534, respectively. The K-RSBQ yielded a low correlation with the CARS total score (Kτ = 0.418, p < 0.001). Finally, the K-RSBQ general mood subscale exhibited a moderate correlation with the CARS emotional response item (Kτ = 0.514 , p < 0.001).

Conclusions: The K-RSBQ developed in this study displays adequate psychometric properties and could thus be adapted to evaluate children with RTT. The analyses we presented in this study further support the usefulness of the K-RSBQ in the Korean population with RTT.

Author(s) Disclosures: There is no conflict of interest.