It's critical to establish motivators, needs, and emotions early in participation. But no person is static, and changes in health, circumstance, or even daily life stressors can bring cognitive load, affect engagement, and even impact health literacy levels.

There are obviously many reasons participants withdraw from trials: some, like toxicity or disease progression, can be outside of our control. Some, like visit burden or financial burden, may be best addressed during protocol development.

What's interesting is the other, very frequent withdrawal reasons we identified – general feelings of anxiety or worry, concerns over receiving a placebo, or some participants withdrawing once they feel they've got what they need from a study.