Table 3.

Examples of Common Errors: Why We Need Prevention and Control

Error	Effect on Clinical Trial	Where Problem Occurs	Is Problem Detectable?	Is Problem Preventable?	Where Problem is Preventable
Inaccuracy [35]	Numerator distortion undermining power	In CT	No	Yes	Pre-CT with criteria for accuracy
Dose range [12]	Effective drug dose not tested	In CT	No	Yes	Pre-CT with evidence of effects on mechanism in humans
Lax monitoring: entry criteria not met by subjects [27]	Trial report misrepresents subject sample	In CT	No	Yes	Pre-CT with training and In CT with off site evaluators