Across England, nearly half of appointments in October (49%) took place on the day they were booked.
However, 640,000 appointments, making up 3% of the total, took place more than 28 days later.
The data does not include appointments which are typically booked in advance, such as medication reviews, and practice groups which had fewer than 100 appointments in October have been omitted.
The analysis reveals a disparity between surgeries, with some in the county performing better than the national average.
But some groups in Northumberland were much worse than average, such as White Medical Group in Ponteland, where 11.9% of patients had to wait more than 28 days for an appointment, and Cramlington Medical Group, where 8.2% of appointments took longer than 28 days to materialise.
There are several factors that influence the length of time a patient has to wait for an appointment, including availability at the practice, patient availability and the urgency of the issue.
The British Medical Association, the trade union for doctors, said the monthly figures were the “highest level of GP appointments on record”.
And the Royal College of GPs said the figures showed “how hard GPs and their teams are working to deliver increasingly complex care to a growing number of patients, against a backdrop of severe workforce shortages”.
Here are the 21 GP practices in Northumberland with the lowest percentage of appointments involving waits of more than 28 days, all of which performed better than the national average:

. GPs Northumberland
21 GPs in Northumberland scheduled a higher percentage of appointments within 28 days than the national average in October. Photo: Google

. Scots Gap Medical Group
Only 1.7% of 1209 appointments at the Scots' Gap practice were scheduled in more than 28 days' time. Photo: Google

. The Rothbury Practice
Only 1.6% of 1826 appointments at The Rothbury Practice were scheduled in more than 28 days' time. Photo: Google

. Guidepost Medical Group
Only 1.5% of 1209 appointments at the Guide Post practice were scheduled in more than 28 days' time. Photo: Google

. Gas House Lane Surgery
Only 1.5% of 1901 appointments at the Morpeth practice were scheduled in more than 28 days' time. Photo: Google

. Marine Medical Group
Only 1.4% of 5118 appointments at Marine Medical Group's practice at Blyth Health Centre were scheduled more than 28 days later. Photo: Google

1. Scots Gap Medical Group
Only 1.7% of 1209 appointments at the Scots' Gap practice were scheduled in more than 28 days' time. Photo: Google

2. The Rothbury Practice
Only 1.6% of 1826 appointments at The Rothbury Practice were scheduled in more than 28 days' time. Photo: Google

3. Guidepost Medical Group
Only 1.5% of 1209 appointments at the Guide Post practice were scheduled in more than 28 days' time. Photo: Google

4. Gas House Lane Surgery
Only 1.5% of 1901 appointments at the Morpeth practice were scheduled in more than 28 days' time. Photo: Google