Nope. We use Amazing Reminders. I like that it pushes the confirmation to the schedule, so the only people I have to follow up on are the ones that didn't answer either way.
I do call new patient's that have already positively confirmed. We book a new patient consult for 60-75 minutes and it's happened more times than we'd like that they will confirm and still NOT keep the appointment, blowing a giant hole through the schedule. I try to give people ample opportunity to cancel with the appropriate notice so I can at least try and fill the slot.
