Reducing DNAs is a KPI for most trusts.
Doesn't help when the person who you're there to see doesn't turn up themselves. Waiting, along with everyone else they were expected to be seeing is annoying. Some had their ambulance transport rearranged twice, which has to added to the cost.
They were seeing their private patients, at a nearby private hospital, but never thought to tell anyone. Not a one-off event either.
The fact that those booking patients in have limited access to records(Makes things easier), rather than having their own staff handling appointments doesn't help.