Parts of the health service in Wales - including waiting lists - have got worse since devolution, a report for the BBC has claimed.
Waiting lists for surgery have grown in Wales
Researchers at the University of Nottingham looked at the effect of devolution on public services in Wales and Scotland.
Their report concluded waiting lists had grown since the Welsh assembly took over responsibility in 1999.
First Minister Rhodri Morgan defended the assembly's record, and Welsh secretary Peter Hain said waiting lists were not the sole measure of the success of devolution.
Mr Morgan said that in some areas of the NHS, like cataract surgery, patients in Wales have shorter waits than those in England.
The university report, "Is Devolution Creating Diversity in Education and Health?" was commissioned by the BBC's World This Weekend programme.
It said that although Scotland and Wales spent proportionately more on public services like health and education than was spent in England, acute health services in Wales were failing to meet demand.
The number of people waiting for hospital treatment for more than six months in Wales had risen from 6,000 to 68,000 since 1997, it pointed out.
"Wales performs especially badly in waiting lists and appears to have on-going financial problems and poor distribution," the report said.
"These are very early days in the life of the devolved administrations.
"Making real changes takes considerable time.
Peter Hain said NHS waiting times were 'negative' for Wales
"Wales was already performing badly. In some respects these problems have become much worse since devolution.
"The acute sector is failing and waiting lists have risen."
Rhodri Morgan told BBC Radio Four that the Welsh NHS had different problems from the health service in England and said that improvements had been made in some areas.
He added: "(Policy is) not different for difference's sake, it's different because you have a different set of problems.
"The biggest difference between Wales and England is in the pattern of hospital use.
"Thirty-five percent of English patients go into hospital through accident and emergency, it's 55% in Wales.
"We haven't created that situation, it's just a different pattern of hospital use.
Rhodri Morgan defended the assembly government's record
"In cataract surgery, we have shorter waiting lists than those in England. We have a four month target compared to six months in England."
Welsh Health Minister, Jane Hutt, added: "We are doing things differently in Wales.
"If you are between 18 and 25, for example, you can get a free prescription. You can't in England.
"We've got a burden of ill-health, we've got an ageing population, we've got health inequalities, that has to be at the front of my agenda."
'Negative for Wales'
Welsh secretary Peter Hain acknowledged that NHS waiting times were a "negative" for Wales, but said they were not the sole measure of the success of devolution.
Mr Hain said: "We have not approached the waiting list problem with the same urgency and success as in England - that's a negative for Wales.
"We are doing other things in the health service - emphasis on primary health care, emphasis on lifestyle - but there's much more to be done and I think there are lessons to be learned on both sides of the border."
He added: "If the sole measure of devolution and the test of its success was waiting lists in the acute sector, then there would be a very serious question mark hanging over the assembly.
"But it isn't the only question because there's been enormous progress and success on other fronts.
"England is starting to follow Welsh policies, for example, in the reintroduction of student grants - that was done in Wales two years ago.
"There are some things we can see Wales is doing better and there are some things which England is doing better."