We opted for a system where users can just come and get started. This saves time and effort. At the same time, we were very attentive to eliminate all possible disruptive factors. For example, we double-secured the internet.
Now, two flexible accesses ensure that users don't even notice a network failure. We have also found a nice solution for the telephone numbers that preserves anonymity: Users can call patients back from anywhere, even with their own phone, and always use the virtual number of the surgery.