Northern Ireland's Health Minister said new figures, which show the number of people waiting more than 12 hours in Northern Ireland emergency departments doubled in the past year, were “simply not good enough”.
Robin Swann has written to the chief executives of each of the Trusts after the latest figures were published on Thursday.
The figures showed that in December 2019, 64,872 people attended emergency departments, compared to 66,636 in December 2018.
However, the number waiting for more than 12 hours was 5,280 — up from 1,991 in the previous year.
It means almost one in 10 who attended emergency departments were waiting for more than 12 hours.
Mr Swann said: “I fully recognise that there are no quick or easy solutions. As with other parts of the health service, sustained investment is required alongside reforms to the way services are delivered.
“One of the key issues is the increasing number of older people attending emergency departments and experiencing long waits, many of whom will require hospital admission.
“Another priority is the development of community services to facilitate discharges of patients who are well enough to leave hospital.
“This is in the best interests of the patients and will also alleviate pressure in emergency departments and throughout the system. This will require investment in the social care workforce.”
SDLP health spokesperson Sinead Bradley said the figures painted a bleak picture.
“Our health service is very clearly in crisis and the solution must be sustained investment and service transformation,” she said.
“Hard working staff are at breaking point and working under intolerable pressure. We must address this crisis for the benefit of staff and patients.”
During December nurses staged an unprecedented walkout in industrial action over pay and conditions. Around 15,000 healthcare workers took to picket lines in wide ranging strike action.
Sinn Fein MLA Colm Gildernew said he was “deeply concerned” by the figures.
“It is clear that the hard working health and social care staff are struggling with the huge pressures.
“We need an end to the 10 years of Tory cuts to public services which have created the crisis in our health and mental health services,” he said.
“For the health minister to address emergency waiting times, he needs the funding to transform the wider health and social care system.”
In December, Altnagelvin Hospital in Londonderry had the longest average waiting time from arrival to admission to hospital of 10 hours and 34 minutes.
The Royal Belfast Hospital for Sick Children reported the shortest average time of four hours and 11 minutes.
No patient should wait longer than 12 hours in any emergency department, government targets state.
The figures show 4.8% of all people attending emergency departments in December 2019 left before their treatment was complete.
Mr Swann said: “Looking to the longer-term, I welcome the fact that the department is progressing a clinically-led review of urgent and emergency care, with a view to transforming services.
“An initial report is expected shortly, which will outline the current challenges and explore some potential solutions.”