Missed GP appointments in St Helens cost the NHS thousands of pounds a day, new figures reveal.
Patients failed to attend 3,342 face-to-face consultations with doctors and nurses in December, NHS Digital data shows.
Across England, the average cost of an appointment is £30, meaning no-shows in St Helens cost the NHS an estimated £100,300 over the month - equivalent to the annual salary of four full-time nurses.
And with sessions usually lasting around 10 minutes, unattended appointments meant GPs and other practice staff wasted 557 hours of consulting time.
The Royal College of GPs said missed sessions are "a frustrating waste of resources" for GPs, and other patients struggling to secure time with their doctors.
In December, a total of 51,993 face-to-face consultations were booked with GPs and other practice staff in the St Helens Clinical Commissioning Group.
Of them, one in 16 was missed without the patient calling in to cancel or reschedule.
Cancelled appointments are not included in the figures, as the surgery can offer those slots to other patients.
According to the RCGP, practices are increasingly using electronic methods, such as text reminders, to encourage patients to keep appointments or cancel them in plenty of time.
RCGP chair Professor Helen Stokes-Lampard said: "We would urge patients to let us know if they can't attend appointments as soon as possible, so we can offer that time to someone who really needs it.
"Many patients are waiting far too long for a GP appointment, and we can all do our bit to help."
More than a million patients failed to attend appointments in England in December, racking up estimated costs of more than £30 million.
The British Medical Association said it was vital that appointments were not wasted at a time of intense pressure on the NHS.
The association's GP committee chair, Dr Richard Vautrey said: "We believe that the NHS should make clear to the public that, given current pressures on the health service, patients should make every possible effort to attend or rearrange their appointment to avoid time and money being wasted."
NHS England has urged patients to do their part to cut down on missed appointments.
Primary Care director Dr Nikki Kanani said: "Our message is clear: if you cannot make it to your appointment, or no longer need a consultation, please let your practice know in advance."