A reminder that only says "see you Tuesday" gives a patient who cannot come nothing to do except not come.

Add one link to move the visit, and most of those patients will take it.

Timing beats wording

Two days before works best for most visits. It leaves time to offer the slot to someone else.

Where to start

A small clinic can start this in an afternoon. Change one thing, watch it for two weeks, then decide whether to keep it.