People failing to turn up to their hospital appointment in Sheffield is costing the NHS millions every year.
Shock figures show 100,685 out-patient appointments at Sheffield Teaching Hospitals NHS Foundation Trust were missed in 2016/2017.
The statistic equates to over seven per cent of all appointments and hospital bosses say the number of missed slots equals the entire work load of 26 doctors in 12 months.
Sheffield hospital chiefs said they could not say how much the missed appointments cost exactly but the figure is understood to run into the millions.
The Trust, which runs the Northern General, Royal Hallamshire, Weston Park cancer hospital, Jessop Maternity Wing and Charles Clifford Dental Hospital, is urging patients to contact them to rearrange slots if circumstances change.
The Taxpayers' Alliance, a pressure group who campaign against waste in the public sector, said missed appointments in hospitals 'waste precious resources' while 'depriving a fellow citizen of medical attention'.
Kirsten Major, deputy chief executive at Sheffield Teaching Hospitals NHS Foundation Trust, said: “We understand that circumstances sometimes change and people may not be able to attend their appointment, but we would always rather re-arrange the appointment over someone not turning up.
"If we know in advance we can use the appointment slot and staff time to see another patient who is in need of our care and treatment. Patients can cancel their appointment via our text reminder messages and can ring the number on their appointment letter. We almost always manage to rebook an appointment slot with another patient and use valuable clinical time to see patients in need of care.”
John O'Connell, chief executive of the TaxPayers' Alliance, said: "People need to remember that being free at the point of service in no way means free service. A huge amount of taxpayers' money goes into running the NHS, so barring emergencies, people need to make sure they attend pre-booked appointments.
"A missed appointment is not only a waste of precious resources, but it also means depriving a fellow citizen of medical attention."