After some of your suggestions, we have updated authorship policies in PROMISE:
Authors in the main paper: centers providing 40 patients without missing data and at least 20% moderate-to-severe: 1 author, centers providing 80 patients without missing data and at least 20% moderate-to-severe: 2 authors. The other authors will be listed as collaborators (2 per center, the PROMISE study group). The final journal may restrict the number of authors, in that case authors will be chosen according to the number of patients included, up to the maximum number of authors allowed by the journal
Authors in collateral studies: you can always use data from your own centers for your studies not involving the PROMISE scale, and you will decide the authors. Collaborators contributing with 40 patients or more will have the possibility of collateral studies with the centers from a particular region/country, you will have 4 authors from your centers, 2 authors from the other center of that region/country and 1 from the designers of PROMISE. Authors contributing with 60 patients or more will have the possibility of collateral studies with the whole database. Authorship: the collaborating center will have 6 co-authors for their collateral study (including first and last author), 1 from the designers of PROMISE and up to 6 authors from top-collaborating centers. A scientific committee will review the proposal, and if OK we will share the database with the center. Timing is important: centers who claim first to perform a specific study after reaching the above mentioned threshold, will be on charge of that study. We will allow 1 collateral study per center. There will be a 6-month deadline for the draft of the paper after receiving the database.