A woman from Armagh County with complex medical needs stated that her quality of life has improved "immeasurably" since moving to Wales to access shorter medical waiting lists last year.
Felicity McKee, 28, who has fibromyalgia and osteoporosis, said she is not sure if she will be able to go home to Northern Ireland.
"If the healthcare system remains as it is, I can't go back," he told BBC News NI.
On Wednesday, a panel of experts published a damning report on waiting lists.
The Nuffield Trust cited a "tight command and control culture at the heart of the healthcare system" and said "the lack of ambition is hindering waiting times".
Stormont's Health Department said it did not comment on individual cases.
However, he said that a significant investment was required to address the backlog, adding that he could not spend money he did not have.
"My treatment was chaotic"
Ms. McKee has had complex medical needs since she was hospitalized after a heart attack on her 21st birthday.
He also suffered from depression and anorexia.
It was put on the waiting list for a specialist dietician for eating disorders in 2012.
He had not yet had access to it when he left Northern Ireland in 2018.
In recent years she had been on three separate waiting lists.
Describing his treatment as "chaotic", he said: "I went from one person to another and felt that nobody really wanted to deal with me.
"Sometimes I thought I was on a list and then I would have learned that I had been taken away.
"The physiotherapist I referred to did not want to treat me because of my osteoporosis.
"The specialist occupational therapist said I should attend a pain clinic – so I wasn't eligible for the pain clinic."
& # 39; Doctor shocked by medical history & # 39;
In a letter seen by BBC News NI, Ms. McKee was refused for a referral to a pain management program because of her mental health problems.
This move was challenged by her family doctor, who told the Southern Health and Social Care Trust that she believed she had been discriminated against.
They said "it deserves a face-to-face evaluation … as I'm sure you offer to other patients".
McKee said that her family doctor and other doctors who "did their best" showed great support, but considered that there was "no joint approach".
Last year, he was traveling to England to visit a friend when he fell ill on a plane and was admitted to the Bristol hospital.
There, he said, a doctor evaluated his medical history and "was shocked" by the level of medical care he had received in Northern Ireland.
"He recommended that I move to England for better treatment," he said.
"Finally taken seriously"
In England, waiting lists are much shorter than those in Northern Ireland.
Even in Wales, the next worst performer, according to the Nuffield Trust report, a patient is almost 50 times less likely to wait over a year for assistance than Northern Ireland.
Ms. McKee subsequently applied for and won a scholarship at the University of Swansea, where she started a PhD in September.
Since then his treatment has been "unrecognizable" from what he received in Northern Ireland.
"In Wales, I was immediately assigned a case worker who was able to combine the points of my medical history," he said.
His physical and medical care has been "treated as a whole rather than taking every issue in isolation".
"I have a walk-in physiology department in the local hospital, I have a direct line for a mental health crisis team.
"I feel like my illness was finally taken seriously and I get the care I need and my life has improved thanks to that."