Clinical Study attributes
The overall purpose of this study is to develop a broad-based (i.e., multiple domains) behavioral outcome measure for children between the ages of 3-18 years with Rett syndrome (RTT). The innovative approach of this proposal consists of integrating the process of developing a behavioral questionnaire to an ongoing large-scale data collection project. The Natural History Study of Rett Syndrome and Related Disorders (RTT5211) is a project that collects data on diverse aspects of the clinical evolution of individuals with RTT and related disorders. This project will serve as the basis for recruitment of subjects and it will also provide key demographic and clinical data for cohort characterization and for determining clinical relevance of the instrument (RettBe). An initial 100-subject cohort will allow for the testing with one rater of RettBe 1.0, a 50-item questionnaire formed from existing measures, a panel of clinicians and behavioral experts in RTT, and a focus group of parents and caregivers of children with RTT. Scores on RettBe 1.0 will be statistically analyzed to determine their psychometric properties, including its content validity. Items that do not meet psychometric standards (e.g., ceiling effect) will be eliminated. Additional items will be added if the parental survey attached to RettBe 1.0 or clinician input suggests so. The resulting modified assessment, called RettBe 2.0, will be administered to a larger (validation) cohort of 300 participants. RettBe 2.0 will also be subjected to analysis of psychometric properties. RettBe 2.0 will also be administered to two raters per subject, in order to determine inter-rater reliability. In addition, these raters will be completing other behavioral and clinical measures for further evaluating the validity of RettBe 2.0 as well as for determining its clinical and functional significance. Finally, the investigators will obtain input from a panel of clinicians (site PIs and their designated clinicians) about content validity and clinical impact. The resulting version will be released as RettBe 3.0.
