The think tank found there were variations of as much as 400% for some for routine operations, such as hip and knee replacements.
In addition, the rate of tonsillectomies in Coventry was 100 times higher than in Kingston and there was a three-fold variation in cataract replacement rates.
But the Kings Fund warned that it will be more difficult to accurately measure these variations once GPs take on commissioning.
‘Moves to GP commissioning raise some practical and technical issues with respect to health care variations, not least the unit of analysis,’ the King’s Fund report said.
‘[PCTs] replacement with GP commissioning consortia creates new boundaries that will require reworking.’
The think tank fears variations could be dealt with in ‘crude ways’ by PCTs and commissioning consortia if detailed, accurate information is not available for analysis. This could include cutting access to certain procedures with an above average admission rate.
GPC deputy chairman Richard Vautrey says that if changes to GP practice boundaries go ahead the situation will become more muddied.
‘There’s no question that with boundaries changing, including the added complication of practice boundaries being removed, that it will be difficult to utilise the information properly,’ he said.
Despite the technical complications around patient data the report does suggest that GP’s clinical knowledge may lead to some reduction in variations.
He added: ‘GPs will be able to take a more clinical approach to these decisions and be able to question them much more robustly than perhaps NHS managers are at the moment.’