Most key NHS targets have been missed for at least seven years across the UK, OceanNewsUK research shows.
The review of records going back 20 years also reveals Northern Ireland and Wales have never met the four-hour accident-and-emergency (A&E) target.
The analysis focused on the three key hospital targets, covering A&E, cancer and waiting times for planned care.
Combined, the length of time during which the targets have been missed tops 100 years.
In the past seven, the only one to have been met is the A&E target in Scotland - and that was during lockdown in 2020, when the number of visits to A&E plummeted.
All four nations said improving waiting times was a priority and investment was being made.
But King's Fund think tank chief analyst Siva Anandaciva said the findings should "act as a wake-up call".
"These are the key totemic targets," he said. "The length of time they have been missed is incredible."
Patients groups warned the delays were putting patients at risk.
Patients Association chief executive Rachel Power said the analysis showed the NHS was in "permacrisis".
"The health of many deteriorates while they await treatment and their problems become more complex," she said.
"This means they will need more time and resources to treat them when they are finally seen, at great cost to the patient and NHS."
Kate Seymour, of Macmillan Cancer Support, said: "The impact this is having on people living with cancer, their families and friends is nothing short of heartbreaking. They deserve better."
British Medical Association leader Prof Philip Banfield said the figures showed the "dire decline" of the NHS during the years of austerity.
Services were "stretched beyond their limits" across the UK, he said.
"Front-line staff are unable to provide the care they've trained so hard to undertake and that patients so desperately need," Prof Banfield added.
'Worst time of my life'
Whether waiting in A&E or for cancer care to begin or an operation, the impact of significant delays on patients is immense.
Ian Binns waited four months for cancer treatment for bowel cancer - twice as long as he should have.
During this time the 66-year-old, from Nottingham, went from stage one to late stage four.
He described the wait as the "worst time of my life".
"I would wake up every morning wondering if I had a future."
His cancer is now incurable as it has spread. "Our greatest tools are rapid diagnosis and timely treatment. Where was the help when I needed it?"
David Corbitt's wait did not have such a devastating effect.
But he still described the experience as awful when he went to A&E because of concerns over a potential heart problem.
He was advised by an out-of-hours GP to seek help after feeling unwell - he was light-headed and was struggling with his coordination.
The 66-year-old, from County Tyrone in Northern Ireland, got a friend to drive him straight to hospital. "I hadn't been to an A&E unit for a few years and I was surprised how busy it was. There were people everywhere.
"It was an evening and I spent 13 hours - the whole night - sitting there on a chair before I was seen. It was awful."
He eventually underwent tests and was discharged home.
"The staff were doing their best, but there was not enough of them. It should not be like this, he added."
''Unacceptable waits'
The Department of Health in Northern Ireland acknowledged the waiting times were "unacceptable" and work was under way to tackle them.
But it said significant progress would require sustained additional investment and the lack of a devolved government meant it was unable to plan for the long-term.
A Welsh government spokeswoman said extra money was being invested, adding: "We have placed a clear focus on those patients with an urgent need and who have waited the longest."
A spokeswoman for NHS England said progress was being made, with the numbers facing really long waits falling and signs the NHS was coping better this winter than last.
Labour, which is in power in Wales, has promised it will achieve the key waiting time targets in England by the end of the next parliament if it wins the election.
The three targets were all rolled out during the 2000s and have been used to track performance ever since.
Each nation decides how they are measured.
The four-hour A&E target is similar between each - but there are significant differences for planned hospital treatment.
For example, in England it is meant to be within 18 weeks of a referral 92% of the time - and that covers everything from knee and hip operations for which patients are admitted through to outpatient appointments.
In Northern Ireland, the target is 13 weeks 55% of the time - but that is just for patients who need to be admitted.
