@rwpark There is a conscious effort on behalf of OHDSI contributors to provide their works under a permissive license (Apache for code, CC0 for documentation) so that these sort of materials can be used without restriction. In particular, TheBookOfOhdsi is released under the CC0 license, which makes it in the public domain in most jurisdictions. If this image is from the book, no additional permission is required. If it’s not in the book yet, someone will probably chime in with a contribution statement, since I’m pretty sure a diagram like this is meant to be in the book but just hasn’t made it yet. Anyway, it’d be great if you would be able to contribute your derivative work back under CC0, your diagram seems an improvement, at least aesthetically. We’re asking contributors to license their creative works under the CC0 so that we could advance the state of the art in medicine and health informatics technology. - Clark