The NHS is a consistently below-average performer for some major illnesses, a new report has found.
It is not doing as well as its counterparts at saving the lives of patients with many of the most common and lethal illnesses, according to an analysis by leading think tanks.
The report, titled How Good Is The NHS?, argues that while the health service has some significant strengths compared to other health systems, it also has notable weaknesses.
Strengths include: the health service being "relatively efficient" with low administrative costs and high use of cheaper generic medicines; it protects people from the heavy financial costs of healthcare and it performs well in managing certain long-term health problems such as diabetes.
Meanwhile, waiting times in the UK appear to be in line with similar countries and patient experience generally compares well.
But the NHS does not have good health outcomes for a number of measures compared to other wealthy countries.
The authors, from Nuffield Trust, the Health Foundation, the Institute for Fiscal Studies and The King's Fund, found that the NHS does not perform as well as similar countries on the overall rate at which people die when successful medical care could have saved their lives.
They found that Britain's health service performs worse than the average in the treatment of eight out of the 12 most common causes of death, including deaths within 30 days of having a heart attack and within five years of being diagnosed with breast cancer, rectal cancer, colon cancer, pancreatic cancer and lung cancer, despite narrowing the gap in recent years.
And the UK also has high rates of child mortality around birth.
They said health care spending in the UK is slightly lower than the average in the 18 comparable countries studied.
And Britain has "markedly fewer" doctors and nurses compared with other countries.
It also has fewer CT scanners and MRI machines.
The authors wrote: "The NHS does not have especially good outcomes relative to other wealthy countries.
"For the most important illnesses in directly causing death, it is a consistently below-average performer."
They added: "The reality is that the NHS is not doing as well as its counterparts at saving the lives of patients with many of the most common and lethal illnesses."
Commenting on the report, Paul Johnson, director of the Institute for Fiscal Studies, said: "The truth about the NHS is that by international standards it is a perfectly ordinary healthcare system, providing average levels of care for a middling level of cost.
"Access is good and people are protected from high costs, but its performance in treating people with cancer is poor, and international comparisons suggest too many people in the UK die when good medical care could have saved their lives."
Nigel Edwards, chief executive of the Nuffield Trust, said the report paints a mixed picture, while Dr Jennifer Dixon, chief executive of the Health Foundation, added that the UK has "middling funding and middling performance overall".
Chris Ham, chief executive of The King's Fund, added: "The UK stands out in removing financial barriers to people accessing care but needs to do better in improving health outcomes."
An NHS England spokesman said: "Although the NHS has been under great pressure, this report shows once again that our health service provides outstanding care for many conditions in a way that is both fair and efficient.
"But the report also rightly highlights areas for further improvements, which need to be addressed head on in the NHS' long-term plan for the decade ahead."
A Department for Health spokeswoman said: "As this report rightly points out, the NHS is world-leading in providing patients with high quality care, free at the point of use."
She added: "We are taking strong action to help people live longer and healthier lives - cancer survival is at a record high while smoking rates are at an all-time low, and the independent Commonwealth Fund has ranked the NHS as the best and safest healthcare system in the world out of 11 countries."
- The report, How Good Is The NHS?, has been published for the BBC as part of their programming for the NHS's 70th birthday.