Three parts of the country will have clinical commissioning groups larger than the primary care trusts they will replace.

Update - 13 December, 2012 - HSJ publishes interactive commissioning system map

HSJ has launched the first comprehensive interactive map of the reformed NHS commissioning system, showing critical details about the new organisations, including their leaders, performance, budgets and size. View it here

CCGs in the South West, North East and London will be larger on average than the PCTs from which they take over next April, although in the North East and London PCTs have been clustered for several years.

The average population coverage of a CCG in the South West is more than twice that of groups in the South Central and South East Coast strategic health authority areas.

In both South Central and South East Coast, CCGs cover a much smaller average population than the PCTs they replace.

HSJ’s analysis follows the announcement last week by the NHS Commissioning Board that it has finalised the number and make-up of CCGs.

There may be changes to the 212 CCGs – for example, practices moving between groups – but they are expected to be

The board also announced which CCGs would be included in each of the four authorisation “waves”, intended to ensure that the great majority of the NHS commissioning budget is transferred to the groups by next spring.

Seventeen per cent of CCGs will be included in the first authorisation wave, due to be completed by October.

Thirty-three per cent will go in wave two, which has a deadline of November. Wave three (December) has 32 per cent of CCGs and wave four (January) 19 per cent.

Leading the way are the North West and Yorkshire and the Humber SHAareas, which both have over 60 per cent of CCGs in the first two waves. Bringing up the rear are East of England and South East Coast, which have over 60 per cent in the last two waves.

Commissioning board director of commissioning development Dame Barbara Hakin told HSJ those in the final waves were as likely to be successfully authorised as others, and said some had to changed waves to fit commissioning board schedules.