A re-populate button is useful for patients so that they can have their previously typed information added to other sections of forms without spending extra time re-typing it all.
It is also useful to offices because it eliminates time spent with patients before appointments filling out forms, as well as sifting through calls of patients who complain about the amount of time it took them to complete a form that asked for the same information.
For example, our patients have to type their name, DOB, Address, Phone numbers, Email, etc in our new patient information forms. Then we ask them to specify who is considered the responsible party for their account. If it is not themselves (ie. child is a new patient, and parent is responsible), they need to fill in the same information about the responsible party. If the patient is also the responsible party, they must fill out the same information a second time -- if there was a re-populate button, it would allow them to check box themselves and then remove the required information section. Most of the time, the responsible party at least lives at the same address and will want to re-populate that portion of the form.
The responsible party information is required because as an office, we need to know who to bill for services.
If we were to make the responsible party information not required, most patients would not fill it out at all. Therefore, we would need to bombard them with calls or emails until we were able to reach them and then get all the information after the fact.