Wales' failure to transform its health service in recent years is proof of the success of the government's reform programme in England, former Number 10 health adviser Simon Stevens has claimed.

Mr Stevens, president of private health provider UnitedHealth Europe and visiting health policy professor at the London School of Economics, told the Chartered Institute of Public Finance and Accountancy conference there is evidence that extra NHS funding in England is resulting in improved services.

'Waiting times for outpatients and inpatients are falling, and we are on track for a 20 per cent drop in premature cancer deaths and 40 per cent drop in cardiovascular deaths by the end of the decade, ' he said.

But extra spending alone is not enough to transform quality, he stressed, arguing that Wales, which has rejected the 'reform mix' introduced in England, has failed to demonstrate the same successes.

He also drew a comparison with the US, where evidence suggests there is no automatic link between extra spending and improved quality.

Mr Stevens also urged the health service to improve its purchaser function, and target commissioning more efficiently. He said the purchasing function in the NHS is 'very weak' and that 'unless it is enhanced, care will be skewed'.

He said commissioning bodies need to produce profiles of patient demand at GP practice level and find imaginative ways of treating patients with multiple chronic conditions, who consume disproportionate amounts of NHS care.

Practice-based commissioning 'will not do the trick', he added, arguing that the scheme is weaker than the GP fundholding model in terms of scope, management support and accountability.