The NHS Confederation has defended primary care trusts' apparently poor performance in the Healthcare Commission's annual health check, saying the results do not compare like with like.
PCT Network director David Stout said the results for reconfigured PCTs - which were worse than those that had been left unchanged - were a warning about the effects of structural change.
'The ones that had been through a major reorganisation performed significantly less well and that's perhaps not surprising,' he said.
'There might be a message in that for people who like to fiddle with structures.
'There is an inevitable consequence for performance.'
Mr Stout said that PCTs faced a much more challenging task because they were measured against 51 targets and performance indicators, compared with 27 for acute trusts and just eight for mental health trusts.
'If you compare PCTs with other healthcare organisations you are not comparing like with like,' he said.
The ratings do not allow PCTs to separate their provider performance from their commissioning performance, he added.