There is clear evidence that the programme to incentivise GPs to provide better quality care has brought improvements, according to the results of a study announced at the NHS Confederation conference.

Professor Martin Rowland, director of the National Primary Care Research and Development Centre at Manchester University, told delegates that research on the quality and outcomes framework, due to be published next week, demonstrates improved care.

The research shows that treatment of both asthma and diabetes have improved more quickly since QOF was introduced. Improvements for patients with coronary heart disease have continued at the same pace as before.

.'Pay for performance is a useful addition to other methods of quality improvement, he said.

Professor Rowland told delegates the drive to increase quality had also improved the use of IT systems.

But he warned that incentives systems could have perverse outcomes. 'Incentives will sometimes drive behaviours that you don't wish to see,' he said.

Designers of incentives schemes should exert caution, he felt,.because 'with any quality assessment or incentive system you end up measuring only what you can measure.

'Such systems should be carefully designed to ensure people are only being asked to improve results in areas they were able to directly influence.'

'If you are going to move this into hospitals you need to think very carefully about who you are incentivising,' he said.

In response to a question from the floor about whether QOF helped address health inequalities, NHS North West chief executive Mike Farrar admitted it had not been effectively built in to the system.

'The way QOF works and the way we designed it could have been so much better in terms of tackling inequalities,' he said.