Table 4 Advantages and challenges of generic and comparison-specific case report forms
CRF type | Generic | Comparison-specific |
|---|---|---|
Advantages | • 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 |
Challenges | • 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. |