The appointments go through a range of statuses which indicate where they are in the system.
|The normal status when an appointment is created.|
|A message has been generated and might be sent.|
|The system has confirmed that the message has been sent.|
|The appointment is confirmed, (the patient replied 'Ok').|
|The appointment has been cancelled.|
The Acknowledged Sent is probably the most important status as it means that that mobile phone has received that message, (although, we can't tell if it has been read or not).
If an appointment is on this status and they are due to turn up today but have not confirmed their appointment then you probably should call them and/or cancel their appointment.
Those still in the white Sent status should also be called but probably not cancelled, as they will not have received a message.
Please also note, you can manually confirm an appointment at any time.