This is one of the reports I send to our front desk receptionist extraordinaire every month. We found it's easier to keep up with it when there's only a handful of names on it.
Anne-Marie Family Medicine Whatever Someone Else Isn't Handling Manager
I add the terms for Demographics = Inactive is False and time >36 months. We do this routinely and send them all letters. If they don't respond, we inactivate. This keeps our patient panel fresh and accurate as to how many are active patients.