Participant identifiers
Every randomisation or Red Pill system must have a participant identifier to uniquely identify participants in the study. You will need to decide whether this will be a pre-existing identifier (such as screening number or ID from another study database), or will be a new identifier created within the system.
Pre-existing identifier
If the identifier already exists, you will need to enter the value in the randomisation or study entry form. The value will always be validated to ensure it is unique, i.e. hasn't been used before in the system. Optionally the format can be validated to make sure it fits the expected pattern.
Validation error when entering a participant ID
Generated identifier
Alternatively, the participant identifier can be generated when the randomisation or study entry form is saved. The format of the generated identifier can be specified. Note that the identifier is generated using an algorithm and does not come from the randomisation list.
Autogenerated participant ID as shown when adding form
Autogenerated participant ID on saved form
Examples
Here are some common participant ID formats:
| Format | Description | Examples |
| N | Incrementing number | 1, 2, 3, … |
| NNN | Incrementing number with leading zeros | 001, 002, 003, … |
| Pre-NNN | Study prefix and incrementing number | SE001, SE002, SE003, … |
| S-NNN | Site identifier prefix and incrementing number (across study) | 01-001, 01-002, 04-003, 02-004, … LE-001, LE-002, BT-003, MK-004, LE-005, … |
| S-MMM | Site identifier prefix and incrementing number (within site) | 01-001, 01-002, 04-001, 02-001, … LE-001, LE-002, BT-001, MK-001, LE-003, … |