Hi Pat,
I would also add that timing is important. Building and maintaining relationships with stakeholders across all levels is important to successful stakeholder engagement. However, not all stakeholders need the same level of engagement all of the time. For example, national level stakeholders may play a key role in post-trial access. They need to be engaged throughout the trial process however will play a bigger role in securing access to products and services when a trial is over.
Prioritizing stakeholders is a good way to see WHO you have to engage and WHEN is the best time to focus engagement efforts with them. A priority grid will change throughout a trial so it is important to continue to evaluate stakeholder prioritization as well as the stakeholder advisory mechanisms being used.