Validation of the Observer-Reported Communication Ability (ORCA) measure for individuals with Rett syndrome.

PURPOSE: The study goal was to validate the Observer-Reported Communication Ability (ORCA) measure for use with females with Rett Syndrome (RTT). METHODS: Qualitative interviews, including concept elicitation and cognitive interviewing methods, were conducted with 19 caregivers of individuals with RTT ages 2 and older. A quantitative study was then conducted in 279 caregivers to evaluate construct validity and reliability. RESULTS: After minor modifications were made, the modified ORCA measure was well understood and captured key communication concepts. Quantitative data showed evidence for reliable scores (α = 0.90, test-retest intraclass correlation = 0.88), minimal floor and no ceiling effects, and strong correlation with the Communication and Symbolic Behaviors Scale (r = 0.73). CONCLUSIONS: This study provided initial support that the modified ORCA measure is an acceptable caregiver-reported measure of communication ability for females with RTT. Future work should include evaluation of longitudinal validity of the measure and its associations with clinician- and performance-based measures in diverse samples.

Validation of the Observer-Reported Communication Ability (ORCA) Measure for Individuals With Angelman Syndrome.

There is a critical need for high-quality clinical outcome assessments to capture the important aspects of communication ability of individuals with Angelman syndrome (AS). To center the perspective of caregivers, our team developed the novel Observer-Reported Communication Ability (ORCA) measure using best practice guidelines, with the goal of developing a measure that could be administered to caregivers directly without the need for a certified administrator for use in clinical trials. To refine the draft measure, we conducted two rounds of cognitive interviews with 24 caregivers and a quantitative study including 249 caregivers. The results from both studies support the overall content validity, construct validity, and the reliability of the ORCA measure for individuals with AS > 2 years old for use in research contexts. Future work should explore the responsiveness of ORCA measures to changes over time in a diverse sample.

Exploring Communication Ability in Individuals With Angelman Syndrome: Findings From Qualitative Interviews With Caregivers.

Communication deficits have a substantial impact on quality of life for individuals with Angelman syndrome (AS) and their families, but limited qualitative work exists to support the necessary content of measures aiming to assess communication for these individuals. Following best practices for concept elicitation studies, we conducted individual qualitative interviews with caregivers and clinicians to elicit meaningful aspects of communication for individuals with AS. Caregivers were able to discuss their child's specific communication behaviors within a large number of expressive, receptive, and pragmatic functions via numerous symbolic and non-symbolic modalities. These results aligned well with published literature on communication in AS and will be used to inform the design of a novel caregiver-reported measure. Future studies on communication in individuals with AS should focus on gathering quantitative data from large samples of diverse caregivers, which would allow for estimations of the frequency of specific behaviors across the population.