For comparison study design and analysis to establish performance characteristics related to the accuracy of the candidate test, there are these appropriate FDA-recognized consensus standards:
- For quantitative tests: Clinical Laboratory Standards Institute (CLSI) EP21, CLSI EP27
- For qualitative tests: CLSI EP12
These standards include discussion of the importance of selecting an appropriate comparative method (CM) and describe quality hierarchies of preferred CM types for quantitative and binary qualitative tests. Comparison to higher quality CMs (e.g. reference methods or methods traceable to higher order references), when available, provides more absolute information about the accuracy of the candidate test while comparison to lower quality CMs may provide only relative performance information. Where there is no generally accepted CM for an IVD device type, the use of a legally marketed predicate device or other well-documented method as the CM would generally be appropriate. FDA recommends discussing the selection of an appropriate CM as part of a Pre-Submission prior to conducting the comparison study.