Missed appointments are costing hospitals more than £5 million a year.

Brighton and Sussex University Hospitals NHS Trust recorded almost 45,000 patient no-shows between April 2011 and the end of March.

“Did not attends” have a knock-on effect on waiting lists as well as the financial impact of wasting staff time.

Some absences were legitimate, with patients either not getting letters confirming their appointments on time or being called away to deal with an emergency.

However, many did not turn up because they had forgotten they had an appointment or did not need one anymore but had not told anyone.

The trust runs Royal Sussex County Hospital, Sussex Eye Hospital and Royal Alexandra Children's Hospital in Brighton as well as Princess Royal Hospital and Hurstwood Park Neurosciences Centre in Haywards Heath.

It calculates that the average cost of a missed appointment is £129, which works out at approximately £5.8 million a year.

However, managers say the numbers are falling as there had been more than 50,000 missed appointments the year before.

They are trying to avoid the extra cost of no-shows as they struggle to save millions of pounds while dealing with more patients than ever.

They are also fighting a £325,000 fine imposed by the Information Commissioners Office for a breach of the Data Protection Act.

Work being carried out to bring numbers down includes online cancellation forms and sending patients text messages.

Some outpatient departments also ask hospital volunteers to call patients a couple of days before their appointment to remind them.

They have done this for rheumatology, diabetes and maxillofacial departments and this is likely to be extended in the future.

A trust spokesman said: “The number of unattended appointments has been coming down.

“Most departments make an allowance for missed appointments when booking clinics and so there are rarely periods when staff are not seeing patients.

“Any ‘free’ time created by missed appointments will be used by staff to undertake other clinical responsibilities or paperwork.”