Last month, some 2,084 patients had to wait on trolleys for up to 12 hours for emergency treament at Craigavon Area Hospital, while a further 170 had to wait more than 12 hours at Antrim Hospital’s casualty department.
Both hospitals have broken NHS care rules, which state that patients should be treated or admitted within four hours.
The Antrim waiting times were amongst the worst for Northern Ireland’s A&E departments.
The latest figures published by the Department of Health, Social Services and Public Safety (DHSSPS), show that the hospital waiting times continue to spiral.
The overall performance of A&E departments has also worsened since the last quarter with 75% of patients treated or admitted within four hours - breaching the government’s 95% target.
In England just over 92% of people were seen within four hours in October, compared to nearly 95% in Scotland and just under 84% in Wales.
The figures vary widely between hospitals in Northern Ireland.
At the Royal Victoria Hospital (RVH) in Belfast, figures improved significantly, with only five people recorded as waiting more than 12 hours in October and November of this year. However, the numbers show that Antrim Area Hospital’s waiting times have deteriorated to 258 in the past two months.
At the Ulster Hospital in Belfast, numbers jumped from three in 2014, to 93 last month.
The total number of patients attending hospitals has also increased, rising from 55,000 in November 2014 to 60,000 this year.
The Health and Social Care Board said it was working with the trusts to provide better emergency care services over winter.
The board said it has invested more than £10m pounds to improve patient flow, as well as the development of minor injury streams in all emergency departments in Northern Ireland.
It said that while it was unacceptable that anyone had to wait more than 12 hours, steady progress had been made to reduce waiting times since 2011/12 when over 10,000 people waited more than 12 hours.
The board added that individual trusts, including the Belfast trust, had made improvements to waiting times.
Around £4m is being allocated from within the Health Department’s annual budget to tackle the waiting time issue over the winter months.
SDLP’s health spokesman Fearghal McKinney said that he is “not surprised by worrying statistics” which he claims shows “systemic failure to treat patients” within target times.
“What continues to shock us, though, is that the minister, and the department, have continually failed to implement a robust and coherent strategy to deal with increasing demand on the system.
“Already this year we have seen a massive crisis emerge in elective care. This was caused by the minister, and the department, effectively redirecting funds away from elective care into emergency departments.”