Sets of data from individuals in a trial are given unique codes so they can be stored and managed properly. Anonymous coding systems (ACS) use codes that do not relate to personal information that might be used to identify the individual in any way (for example, a participant’s initials or health record number must not be included in the code). This allows individuals taking part in clinical trials to remain anonymous.
Coding can be important to allow tracing of individuals in the future (for example to allow authorised health professionals to follow up on results that come out of trials). To enable this, information about which individual was given which code is usually held securely, for example at a separate location not involved in the trial.