The long-term plan, published in January 2019, suggested PCNs would be 'based on neighbouring GP practices that work together typically covering 30-50,000 people'. NHS England has described groups of this size as 'natural communities'.
But analysis by GPonline of 1,250 PCNs listed in NHS Digital data shows that only 735 (59%) are within the 30,000- to 50,000-patient range. A total of 34% have more than 50,000 patients, while a further 7% have less than 30,000 patients.
Barnsley PCN is the largest in England - with a list of 263,659 patients, more than five times the top end of the 'natural' range. At the other end of the scale, Formby PCN in Southport and Formby CCG on Merseyside, has just 14,679 patients.
A senior GP who was among the architects of the 'primary care home' model of general practice - on which the PCN concept is based - warned earlier this year that networks covering more than 80,000 patients may struggle to have a genuine impact on frontline general practice.
Former National Association of Primary Care chair Dr Nav Chana told GPonline in September: 'Of course it’s possible that PCNs larger than 50,000 patients can still provide personalised care, we’ve got some examples of how that can be done.
‘But if the next step is to say, well actually, let’s increase to 80,000 patients or let’s round up to 100,000 I think there’s a danger of creating more of an organisation rather than a community-facing integration-type approach. That’s because you need to create some bureaucracy within that to build relationships between people.
‘We’ve had examples of going too large in the past four or five years and in some situations that’s worked. But in other situations it hasn’t.'
Some 62 PCNs - 5% of the total - have more than 80,000 patients, while 24 have more than 100,000. This variation in population size is also reflected in significant variation between PCNs in the number of practices they include, and in between CCGs in the number of PCNs they cover.
Some PCNs cover an entire CCG area - while other CCGs have more than 30 PCNs within their boundaries. Meanwhile, 35 PCNs are made up of just a single practice - while in other areas a single PCN includes more than 30 GP practices.
Primary care networks, backed by £1.8bn in funding through the five-year GP contract deal that began in April 2019, are expected to deliver 20,000 support staff to ease pressure on general practice - plus a further 6,000 promised by the Conservatives in the general election campaign.
But former RCGP chair Professor Helen Stokes-Lampard warned earlier this year that there was no guarantee the networks would deliver immediate benefits.
She said: 'PCNs are essentially groups of practices working together and aiming to work with other agencies to deliver improved care for patients - and collaboration can have great benefits, particularly at a time when general practice is facing such intense resource and workforce pressures.
'However, there is no one size fits all approach to resolving the pressures facing general practice, and while structural reorganisation like this can be positive for surgeries with sufficient resources, others will need a lot more support and time to develop.'
Despite the suggestion that PCNs would 'typically' cover populations of 30,000 to 50,000 patients, NHS England said last year that networks 'determine their own size based on what they know will work best for their patients'.