There will be huge variation between clinical commissioning groups’ internal staff numbers and their reliance on independent support services, according to the first analysis of the structure of the new groups.

However, HSJ has also learned CCGs in total are likely to employ significantly fewer people than the independent commissioning support providers which will carry out much of their day-to-day work.

The most recent Department of Health estimates are for 4,200-6,300 staff in CCGs and 8,000 in commissioning support units, HSJ understands.

HSJ examined detailed staff structures provided by a sample of 18 of the 35 CCGs which are being assessed in the first wave of the authorisation process.

Some of the variation in numbers is explained by CCGs’ population size, but much is down to decisions about how much work is contracted out.

NHS Bedfordshire CCG is planning to employ 125 staff, as well as a 20-strong quality team shared with another CCG. Its population is 432,000 so there will be nearly three staff for every 10,000 population.

If all CCGs employed staff at the same rate, the national total would be more than 15,000. That would leave minimal staffing and income for CSUs, and make many of them unviable.

NHS Great Yarmouth and Waveney CCG is another example of a CCG planning to employ a lot of staff, with 55 employees, despite its relatively small population of 230,800.

In contrast, NHS Portsmouth CCG, with a population of 216,000, plans to directly employ only 12.9 whole time equivalent staff. It will share a further 17 with neighbouring CCGs and 18 with a local authority.

NHS East Riding of Yorkshire CCG has a population of 300,000 but is planning to employ only 28 staff directly - fewer than one person per 10,000 population. If that ratio was repeated across England, the total CCG workforce would total only about 4,600, and would be dwarfed by CSUs probably employing about 10,000 nationally.

The variation in the sample is expected to be repeated across other CCGs.

The national reliance on external commissioning support, and specifically for CCGs with few staff of their own, comes despite concern about CCGs becoming reliant on and led by CSUs. Government policy is for CSUs to be privatised by 2016. Meanwhile, only six of the 18 CCGs’ structures have a senior executive nurse post, although a further 10 have a member of staff whose job title includes the words quality or safety.