We have a message via Weave that sends the person a text when their call goes to voicemail after the 4th ring during office hours. It explains that we are sorry we missed their call, but we were either taking care of a patient or on another call. They can text us back to let us know what their call was about or they can leave a message. We also let them know we will call them back shortly.
That is a good solution if you can't get to the phone. I like that Weave text makes it seem like you sent them a quick text and as long as you call them releatively soon after they get it, that is great. We just don't want the patient to feel like we are "too busy" for them.