If you are interested in participating in a particular clinical trial, the first step is screening. Pre-screening takes place during a face-to-face, telephone or online contact. The goal is to verify your eligibility in principle for the study by answering a few questions. The questions cover part of the inclusion and exclusion criteria, which are criteria defined in the study protocol that determine whether you can participate (inclusion) or not (exclusion).

These inclusion and exclusion criteria include, for example, age, gender, type or stage of disease, pregnancy, medical history, failure or success of previous treatments, presence or absence of other conditions, and specific allergies. Questions may also be asked to assess your willingness to undergo certain medical procedures (blood tests, injections, scans, etc.) and the practical feasibility of possible participation: can you come to the hospital regularly, for example?

Pre-screening prevents patients who are not eligible anyway from having to go through the informed consent process and then drop out. So, this step saves time for both patients and researchers.