Abstract
The Community Youth Development Study (CYDS) will evaluate the Communities That Care (CTC) operating system for its effects on alcohol, tobacco, drug use, and other outcomes among adolescents resident in the 24 participating communities. The CYDS employs a combination of both cross-sectional and cohort designs. We use data from an earlier study that included the CYDS communities to estimate power for CYDS intervention effects given several analytic models that might be applied to the multiple baseline and follow-up surveys that define the CYDS cross-sectional design. We compare pre–post mixed-model ANCOVA models against random coefficients models, both in one- and two-stage versions. The two-stage pre–post mixed-model ANCOVA offers the best power for the primary outcomes and will provide adequate power for detection of modest but important intervention effects.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
