Ministers may have to adopt a more 'flexible' approach to GP commissioning if they want it to deliver all their objectives for the NHS, research suggests.

And, says the study, they should 'resist the temptation' to cut transaction costs by adopting 'a single solution for the NHS as a whole'.

A survey of health authority managers conducted by academics at Birmingham University's health services management centre will be unveiled at a conference today.

It suggests that no one model has succeeded so far in improving services across the board.

And, while various models of GP commissioning have helped improve services for chronically mentally ill people and continuing care, fundholding consortia and multifunds have had the biggest impact on waiting times and referrals.

The report comments: 'Given that no single approach performs consistently well, a range of levers and approaches are likely to be needed to deliver the government's objectives for the NHS.'

And it concludes: 'Recognising that the language may change, some of these levers may evolve from the powers currently available to fundholders.'

Linked to this, it says, future commissioning arrangements 'may need to build in scope for different functions to be performed at different 'levels' (such as the practice, the locality and the health authority)'.

The report goes on: 'The underlying policy question that remains to be addressed is whether continuing (and increasing) commissioner pluralism should be tolerated (or even encouraged), or whether the time is now right to reduce the number and type of approaches...

'The challenge as we see it is to find a way forward which enables there to be flexibility in different districts without this undermining the government's commitment to promote equity and reduce transaction costs.

'This suggests the need to rationalise current arrangements over time while avoiding the temptation to adopt a single solution for the NHS as a whole.'

The research, based on a survey of all English HAs, is, says lead author Judith Smith, intended to shed light on managers' views, and takes no account of cost; nor does it examine 'standard' fundholding, which was outside its remit.

'In some ways, perhaps it is not surprising that fundholding and commissioning models are effective in different areas. They were set up to do different things,' says Ms Smith.

'But with greater emphasis in the white paper on performance managing some of these initiatives in a more explicit way, these are important findings.'

The research will be unveiled today at a conference in London on 'The future of commissioning: beyond fundholding', and will be published as a report in the spring.

Mapping Approaches to Commissioning: extending the mosaic. For details phone Birmingham University's health services management centre, 0121- 414 7050.