Do applicants need to confirm all study sites by the time of Letter of Intent (LOI) submission, including sites in a multisite study?

LOIs are required, at a minimum, to propose all study sites by the time of submission. Other sections of the application are informed by information about the sites and the potential participants at those sites. If, after the LOI submission, study sites need to be changed as part of the application submission, approval from PCORI staff must be obtained.