Creating a table lookup for a study allows the system to check for a sequential customized subject ID to give to each subject that is added to the system. For example, a study may require that when a subject is added but fails certain criteria, they get a different formatted ID than the ones that are successfully enrolled and taking part in the study. At the same time, they need to be sequential regardless of the format. A common application of this scenario is with screening IDs versus subject study IDs, where every subject gets a screening ID of <SITEID-00X>, where X is a sequence, but subjects who are successful get a slightly different format of <SITEID-40500X>. The system is able to keep the total population sequential regardless of which of those formatted IDs is assigned.
Subject 1 is successful and gets 301-405001
Subject 2 is successful and gets 301-405002
Subject 3 has an issue but still gets a screening ID of 301-003 - sequenced off the previous two subjects that were successful.
Subject 4 is successful and gets 301-405004
Subject 1 is successful and gets 301-001-4001
Subject 2 is successful and gets 301-002-4002
Subject 3 has an issue but still gets a screening ID of 301-003 - sequenced off the previous two subjects that were successful, but does not get a study ID portion on the end.
Subject 4 is successful and gets 301-004-4003
There is virtually no limit to how the formatting can be specified. Keep in mind, this is different from randomization. It is merely a table lookup to provide a sequenced ID dependent on some sort of criteria. However, it can be used in parallel to a randomization. Let's look at how the examples above can be set up.
Study Administrators can always edit IDs and even clear an allocation from the lookup table if necessary.