This one-size-fits-all mentality was never explicitly mandated. It emerged from a combination of institutional inertia, regulatory caution, and the understandable human tendency to apply familiar solutions to novel problems. If 100% source data verification worked for pivotal Phase III trials, the reasoning went, surely it would work everywhere. If weekly monitoring visits were appropriate for high-risk interventions, why not apply them universally?

The answer, which ICH E6(R3) now makes explicit, is that resources are finite and attention is limited. When everything receives the same level of scrutiny, nothing receives the level it actually needs. The site overwhelmed by monitoring activities for a low-risk trial may have its staff so burdened that they miss genuine problems. Meanwhile, the high-risk trial receiving the same template oversight may not get the intensive attention its complexity demands.

E6(R2), adopted in 2016, introduced risk-based monitoring concepts in its Addendum, marking the first formal ICH recognition that uniform oversight was neither required nor desirable. E6(R3) goes further, elevating proportionality from a monitoring concept to a core Principle that applies across all trial processes.

Principle 7 of ICH E6(R3) articulates this philosophy explicitly: the level of oversight and activity should match the actual risks and importance of what is being overseen.

This one-size-fits-all mentality was never explicitly mandated. It emerged from a combination of institutional inertia, regulatory caution, and the understandable human tendency to apply familiar solutions to novel problems. If 100% source data verification worked for pivotal Phase III trials, the reasoning went, surely it would work everywhere. If weekly monitoring visits were appropriate for high-risk interventions, why not apply them universally?

The answer, which ICH E6(R3) now makes explicit, is that resources are finite and attention is limited. When everything receives the same level of scrutiny, nothing receives the level it actually needs. The site overwhelmed by monitoring activities for a low-risk trial may have its staff so burdened that they miss genuine problems. Meanwhile, the high-risk trial receiving the same template oversight may not get the intensive attention its complexity demands.

E6(R2), adopted in 2016, introduced risk-based monitoring concepts in its Addendum, marking the first formal ICH recognition that uniform oversight was neither required nor desirable. E6(R3) goes further, elevating proportionality from a monitoring concept to a core Principle that applies across all trial processes.

Principle 7 of ICH E6(R3) articulates this philosophy explicitly: the level of oversight and activity should match the actual risks and importance of what is being overseen.