Hi @nbareis, I work at Columbia on the OHDSI project and would be happy to help out with any questions or assistance you may need. Do you have access to Columbia’s instance of ATLAS? If you need help using it–to establish your desired cohort or for any part of the process–please let me know. If you already have established your cohort definition in ATLAS, you can post your study question to the researchers category of this forum to engage people at other institutions who would be willing to run your study on their own databases.