The Health and Social Care Board has said it is analysing statistics to establish how many people on a waiting list may have died because of the delay for treatment.
Some of those deaths may be catalogued under what are described as serious adverse incidents in Northern Ireland's health and social care system. There have been more than 1,000 since 2016.
A serious adverse incident (SAI) is defined as any event or circumstance that led to or could have led to serious unintended or unexpected harm, loss or damage to patients.
There have been 1,428 such incidents since 2016 across all areas of care. It's not known what percentage of these are deaths due to hospital waiting times.
Waiting lists in Northern Ireland have reached record levels.
One in 16 people in Northern Ireland is on waiting lists for 12 months or more, compared to one in 48,524 in England.
The former chief executive of the Health and Social Care Board John Compton said there is a flaw in the system which records the outcome of SAIs.
He said the system is not designed to evaluate the incidents during serious delays in waiting times in the health service.
"It's clearly inconsistent. It goes back to waiting times. When the SAIs are being looked at, I don't think anybody expected that waiting times would be part and parcel of that.
"The way in which the system is set up doesn't look at or doesn't include that.
"You can't have the numbers of people we currently have waiting and not expect that for a number of people, the waiting itself contributes to an adverse outcome. I don't think our system was ever designed for that. We're in a very different place."
A spokesperson for the Health and Social Care Board described as "very challenging" to give a definitive figure around the degree in which waiting lists have been a factor in deaths.
"However, we are treating this issue with the utmost seriousness and there is ongoing analysis to understand the impact further," a spokesperson said.
"Waiting times have been building up since 2014 as a result of wider financial pressures facing the Health and Social Care system, a reduction in the amount of non-recurrent money available to address the growing challenges, and well documented workforce challenges.
"A combination of sustained investment and transformation is required to address the waiting backlog."
Mr Compton explained a serious adverse incident could range from an unexpected outcome in a surgical procedure, such as death, or a wrong organ being removed,
"When something very significant goes wrong in the treatment or care of an individual, staff are encouraged to report that as a learning exercise so that there's the opportunity not to make the same mistake again," he said.
Mr Compton said hospital delays now mean that waiting times are "irrelevant" for patients.
"If you're telling somebody they're going to have to wait two, three or four years to be seen, you could argue there isn't a waiting time at all, you're just not going to get seen," he said.
"There isn't a sense of perspective. No one can consider 220 weeks or numbers that have been quoted as reasonable."