Usually refers to when a clinical trial stops recruiting new patients. Existing patients who are already in the study continue to be followed up as part of the trial. This follow-up can continue for many years if the trial has been designed to look at long-term results. When follow-up for all patients has been completed and the data collected, the trial data can be analysed and reported. Usually, no more information is collected on the patients unless specific ethics approval is granted for the researchers to do so.