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.





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Publication Info

Zigler, Christina K, Li Lin, Molly McFatrich, Nicole Lucas, Kelly L Gordon, Harrison N Jones, Allyson Berent, Jennifer Panagoulias, et al. (2023). Validation of the Observer-Reported Communication Ability (ORCA) Measure for Individuals With Angelman Syndrome. American journal on intellectual and developmental disabilities, 128(3). pp. 204–218. 10.1352/1944-7558-128.3.204 Retrieved from

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Christina Kelsey Zigler

Adjunct Associate Professor in Population Health Sciences

Dr. Zigler is an independent investigator dedicated to improving the ways we measure patient-centered, meaningful health states, specializing in pediatrics, rare diseases, and clinical trials. She also is a methodological co-investigator who supports the application of novel statistical approaches and measurement strategies across a diverse array of studies.

Her methodological expertise includes established qualitative and quantitative techniques (i.e. concept elicitation, cognitive testing, classical test theory, item-response theory) alongside innovative methods (i.e. novel ways to identify meaningful change), to ensure the measures are ultimately centered in the patients’ meaningful experiences. Further, she works in a variety of populations and contexts, including pediatrics, where patient-reported outcome measures empower children to report directly on their own health status, and rare diseases, where a creative and pragmatic approach to measure development is necessary and patient-centeredness is essential.

Areas of Expertise: Health Measurement, Health Behavior, and Health Services Research

Harrison N. Jones

Associate Professor of Head and Neck Surgery & Communication Sciences

Bryce B. Reeve

Professor in Population Health Sciences

Dr. Bryce Reeve is a Professor of Population Health Sciences and Professor of Pediatrics at Duke University School of Medicine.  He also serves as Director of the Center for Health Measurement since 2017.  Trained in psychometric methods, Dr. Reeve’s work focuses on assessing the impact of disease and treatments on the lives of patients and their caregivers.  This includes the development of clinical outcome assessments using both qualitative and quantitative methods, and the integration of patient-centered data in research and healthcare delivery settings to inform decision-making.  From 2000 to 2010, Dr. Reeve served as Program Director for the U.S. National Cancer Institute and oversaw a portfolio of health-related quality of life research in cancer patients. From 2010 to 2017, he served as Professor of Health Policy and Management at the University of North Carolina.  From 2011-2013, Dr. Reeve served as President of the International Society for Quality of Life Research (ISOQOL).  In 2015, he received the John Ware and Alvin Tarlov Career Achievement Prize in Patient-Reported Outcomes Measures.  In 2017, 2018, 2019 and 2021, he was ranked in the top 1% most-cited in his respective field over the past 11-year period.

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