In Hull CCG, there are 3,185 patients per full-time equivalent (FTE) GP - a staggering 80% more than the 1,776 patients per FTE GP in Wirral CCG.
The two CCGs - less than 150 miles apart across the north of England - have the highest and lowest numbers of patients per CCG in the country. Hull's total figure for patients per GP is 42% above the median figure for CCGs of 2,239 - while Wirral's is 21% below.
The figures - part of a wider GPonline analysis of England's most underdoctored areas - shed new light on the disproportionate impact of England's chronic GP shortage regionally, with some areas struggling to attract doctors while others are more able to recruit.
Evidence of the uneven spread of GPs across the country comes as general practice faces intense workload across the board and as official data confirm that England has lost nearly 1,500 FTE GPs - around 5% of the total workforce - over the past five years.
Rising numbers of patients registered with GPs over the same period have left the average GP caring for 11% more patients than half a decade ago - at a time when over the past year general practice delivered an unprecedented 367m apppointments.
GPonline reported earlier this month on polling that found GPs were delivering on average 84% more patient contacts per day than the level considered safe by the BMA - with a record 6m-strong NHS hospital waiting list driving up pressure on practices alongside huge COVID-19 and flu vaccination campaigns.
But while pressure is intense across the profession as a whole - prompting the BMA's GP committee chair Dr Farah Jameel to warn that for many GPs the job expected of them is no longer 'safe, sustainable or possible' - the problems are magnified for GPs working in areas with the highest numbers of patients per doctor.
On a more local level, gaps between PCNs with the highest and lowest numbers of patients per FTE GP are a yawning chasm compared with the differences at CCG level, our analysis reveals - based on data from NHS Digital about the GP workforce and on numbers of registered patients per GP practice.
The numbers range from more than 7,300 patients per FTE GP in one Derbyshire PCN to around 1,100 patients per FTE GP in a PCN in Herefordshire.
Figures for individual PCNs may be skewed in some cases by underreporting - particularly for PCNs made up of just one or two GP practices - and NHS Digital's workforce data are believed significantly to underrepresent locum GPs , which may also give a false impression in some areas.
However, the PCN-level data make clear the extreme difficulties some areas face with their GP workforce, with 141 PCNs - one in nine of the total - facing a ratio of more than 3,000 patients per FTE GP.
Underdoctored areas are clustered together around parts of Lancashire, Yorkshire, Lincolnshire, and in south-east England in Kent and Essex - as well as in other parts of the country. But even within wider CCG areas that appear well-resourced in terms of overall GP numbers, in some cases individual PCNs are struggling, the data show, reflecting the fragility of general practice across the country.
GP leaders called on 10 February for urgent support for GP practices struggling with soaring workload in the face of a workforce crisis - along with talks on a new contract - and have set out plans to consult with the profession on the future of general practice.
Dr Jameel said: 'The pace and scale of demand we are experiencing every day, despite these being intense back in 2019, are now on a level we have never had to deal with before. As a result, every month we continue to haemorrhage GPs from the profession.
'General practice remains excellent for individual patient care, yet it has for too long been underestimated and poorly supported by policymakers.'