GPonline reported exclusively last week on survey findings that suggest 14m appointments are lost each year in England to DNAs - equivalent to more than 60,000 a day.
GPC deputy chairman Dr Richard Vautrey warned that patients were being put at risk by the loss of such a huge number of appointments at a time when practices were increasingly struggling to fit soaring demand into available consultation slots.
So what are GPs doing to combat the rising problem of DNAs?
A total of 12% of respondents to a GPonline poll of more than 500 GPs said they block patients from booking appointments if they repeatedly fail to show up for appointments.
But practices take a variety of approaches to tackling DNAs, from gentle reminders to stern warnings that patients will be removed from their list if they repeatedly miss appointments.
1. Remind patients about appointments
Many respondents said text message reminder services had helped limit numbers of appointments missed. However, from April this year, the DH stopped central funding for the SMS text messaging service that at least one in seven practices relied on to send patients reminders.
For some patients, a text message may not be enough. One GP responding to the survey wrote: 'We have decided this week to contact one patient on the morning of his booked appointment to check he is still planning to attend as he has missed several double appointments.'
2. Book less far ahead
Some practices report that limiting how far ahead patients can book appointments has helped reduce DNAs. One GP said: 'DNAs were a problem when patients could book four weeks ahead. They are much less of a problem now we only allow booking two weeks ahead.'
However, some GPs may feel this solution is difficult to implement. Two thirds of respondents said waiting times for appointments had become longer in the past year at their practice, and one in six said patients now have to wait more than two weeks. High DNA rates were often cited as a factor that made it difficult to reduce these waits.
3. Warning letters
Many practices send letters to patients when they miss appointments. Some are effectively a gentle reminder of the inconvenience this can cause. One GP said: 'Persistent offenders receive letters.' Another said they receive a 'written warning and an alert is added to their notes'.
4. Ban booked appointments
Many practices operate a 'three strikes' policy that triggers a second stage of action to tackle DNAs after three warning letters. Some practices ban patients from booking appointments once they have been warned three times about DNAs.
One GP wrote: 'They get three warning letters, then are only able to make book-on-the-day appointments unless a reasonable explanation is given.' Another said: 'After three DNAs a letter is sent. After a further DNA - no more pre-bookable appointments.'
Another reported: 'We are considering whether we look into this group of patients not being offered appointments, and being told to attend and wait until a GP is available.'
One other practice said it offered 'very few' pre-bookable appointments, and this approach had helped significantly reduce DNAs.
5. Removal from practice list
Some practices take a tougher approach to dealing with the problem, warning patients that after three appointments missed they will be removed from the practice list.
Many of those reporting this type of policy said it would not apply to patients with mental health issues, such as dementia.
One practice said: 'We regularly audit the "top offenders"; these are warned by letter once and a further DNA leads to removal from the list.'
Another said: 'After three DNAs, patients get a warning letter, advising them that if they miss further appointments we reserve the right to remove them from the list.'