The easiest way to do this is to have multiple prongs of communication that say the same thing.
If you’re implementing a new process you might have an e-mail that states in the subject line, “New patient process please use by 5/18.” You might follow this up with a brief article in your corporate newsletter about the new process.
You could also create a quick presentation at each location that shares why you have this new process, how it differs from the old process, and what staff needs to do to get it implemented.
This keeps everything short and sweet, shares what action they need to take, and hits on multiple communication levels that keeps each communication consistent.
When you have multiple locations you need to have tight, high-level communication to ensure the best results.