By Emma Wilkinson
Health reporter, BBC News
NHS funding has doubled since 1997
The NHS in England has improved significantly since 1997, according to the independent King's Fund think-tank.
Its report on the past 13 years praised faster treatment and easier patient access to services.
But Tory shadow health spokesman Andrew Lansley criticised Labour's record in tackling obesity, smoking, alcohol and drug abuse, cited in the report.
Lib Dem spokesman Norman Lamb said more preventative health spending was needed if the NHS was not to be bankrupted.
The report found the health gap between rich and poor was as wide as ever and cancer survival rates, although improving, still lagged behind Europe.
The King's Fund also said the NHS faced a steep challenge in maintaining and standards in an era of tight finances.
In 1997, the health service was suffering from chronic underfunding and patients faced long waiting lists for care, the report said.
In addition, treatment and access to drugs was highly variable across different parts of the country.
Since then, there has been an unprecedented rise in NHS funding, which in real terms has doubled since 1997.
Andy Burnham, Secretary of State for Health, said the NHS was in a "strong position" to deal with future demands.
"The challenge of the last decade was one of expanding capacity so the NHS could finally remove the long waits and give people access but we would accept that the big challenge going forward is to get more from this expanded more resilient NHS."
Liberal Democrat shadow health secretary Norman Lamb said: "The report is right to highlight the massive challenges ahead in getting better value in the NHS.
"If we don't tackle the public health time bomb that faces us and take steps to invest in preventative ill health measures, we could bankrupt the NHS."
The review set out to look at how much had been delivered as a result of the record investment.
It found major and sustained reductions in waiting times with most patients now seen, tested and treated within 18 weeks.
The report also found better access to GPs and other primary care services, although it said more progress was needed on out-of-hours care.
Death rates from heart disease and cancer have fallen substantially, although cancer survival still lags behind other countries in Europe, it said, with earlier diagnosis and access to radiotherapy two issues which need particular focus.
The King's Fund said the creation of the National Institute for Health and Clinical Excellence (NICE) had helped to ensure consistency of care across the NHS, but stressed there were still variations in access to drugs.
More needed to be done on tackling major public health challenges like the use of alcohol and obesity, both of which have risen over the past decade, it said.
"Consumption of alcohol has increased since 1998, accompanied by a rise in alcohol-related hospital admissions and rates of liver disease, suggesting more aggressive, cross-departmental action will be needed in the future.
"The prevalence of obesity is rising in adults and children, despite government targets to halt the increase. There has been improvement in rates of exercise and aspects of healthy eating, but it is too soon to evaluate some of the more recent government initiatives to reduce obesity."
For the Conservatives, Mr Lansley said the report "exposes Labour's failure to tackle our ballooning public health problems".
He added: "They have missed and scrapped their own obesity targets, smoking rates continue to exceed other countries and alcohol and drug abuse are both up."
He also criticised the King's Fund for not facing up to "the fact that while resources have doubled, the performance of the NHS has not improved as it should have done."
The report also found that higher pay costs had absorbed more than half of the increase in NHS funding since 2002 with productivity dropping over the past few years.
With budgets facing a significant squeeze in the future, the NHS must make the most of the substantial scope for savings through reducing lengths of stay in hospital, providing more care in the community and using lower cost drugs, the report concluded.
Professor Chris Ham, chief executive of the King's Fund, said the NHS was in much better shape than a decade ago.
"What we can say with confidence is that the NHS has moved out of intensive care and into active rehabilitation.
"It's on the road to real improvement to deliver world-class standards of care but it isn't there yet."
He said the next government would have to tackle the difficult challenge of building on the improvement and paying far greater attention to prevention of ill health, but with reduced investment.