• Efficient if data requirements are similar across comparisons|
• Data are captured consistently across comparisons
• Capacity to still make sections specific by arm, comparison, sites, patient sub-group, etc.
• CRF changes need to be made on only one set of CRFs, reducing time taken for development/amendments
• Generally fewer CRFs overall
• Efficient if data requirements are substantially different across comparisons|
• Only data required for a single comparison is captured
• Not likely to become as complex as generic CRFs. May therefore be easier for site staff to use.
• Each CRF is easier to maintain for comparison-specific changes
• Not all changes across life of the trial must be included, only those during the lifespan of the CRF
• Adding comparisons/questions.|
- Increasing length and complexity as additional data requirements are added
- Question numbering can become unwieldy if new questions are needed within the existing CRF
- Unanticipated changes may require existing CRF to be redeveloped or a new CRF to be developeda
- Shared control arm participants may be affected by new comparisons requiring conditional questions/sections to be addedb
• Less flexibility in collecting data
- Must ensure CRFs can be relevant for all comparisons
• Changes external to the trial may be more likely to impact generic CRFsc
- Universal coding lists changing the names or values of items on the listd
- Changes in standard of care
• Generic changes will need to be made across specific CRFs separately, increasing maintenance time and risk of errors.|
• More CRFs in total
- Can take longer to train site staff on each individual CRF if they are different from each other
- Version control/CRF tracking. Multiple similar versions with differing version numbers. Data management staff must be more careful to ensure correct version is used.
• If a shared control arm is being used, CRFs for this arm must still capture data required for multiple comparisons whilst ensuring this does not introduce bias; additional questions may lead to events being more likely to be reported or introduce other biases. Some questions may need to be added to all comparison-specific CRFs to avoid this.