Can doctors use calendly or this? I don't think there are HIPPA concerns with appointment schedules and it sure would be nicer that the existing process where you call 5 places to find they're not accepting patients.
Unfortunately, no, those solutions are not built for medical purposes. Even a small practice usually has different types of appointments with different durations and requiring different resources (e.g. some basics can be done by a nurse and many appointments won’t block your X-rays room). Decent appointment management system (AMS) should be not only compliant with data protection regulations, but also have a good feature set.
There are companies like Doctolib in Europe, which build AMS specifically for the healthcare. The company where I work as a CTO decided in the end to build our own AMS to be able to optimize the show rate and to connect AMS to our marketing and ERP - we were not satisfied by anything we have seen on the market.
We are still active users on Calendly nevertheless - it is a good tool for scheduling job interviews and calls with external partners. Would be interesting to see UVP of Calendso in this field.