Bosses at United Lincolnshire Hospitals Trust have apologised after the trust’s A&E performance hit its lowest level of the year.
Latest NHS England figures show the number of patients waiting less than four hours to be admitted or treated at emergency departments in the region fell to 64.2% in October.
The national standard for A&E waiting times in England is 95%.
Bosses at the trust, which has 24 hour A&E departments at Boston Pilgrim Hospital and at Lincoln, and a daytime only service at Grantham, said they had seen a “significant increase in very poorly patients” attending A&E, but admitted that its performance was not “where we want it to be”.
A total of 15,139 patients came through A&E doors across the county last month alone, compared with 13,996 at the same time last year.
The trust recorded its highest performance in September, when it hit 73.1% – nearly 22% below target.
ULHT has not reached the national standard since September 2014.
Simon Evans, director of operations at the trust, said the last month had been a “significant challenge” for the health service.
“Our A&E performance is not where we want it to be and we would like to apologise for this,” he said.
“Over recent months we have seen a significant increase in the number of very poorly patients attending at our A&Es, as well as cases of the winter vomiting bug norovirus.
“This has coincided with a reduction in the number of patients being discharged from our hospitals, which has unfortunately resulted in long delays for some of our patients in A&E.
“We are disappointed, as during September we saw an improvement in our A&E performance and we were recognised as one of the most improved in the country.
“We know both regionally and nationally that October presented significant challenges for the NHS and this is reflected in our performance in October.
“We are working with partner health and social care organisations to ensure our patients receive the appropriate care as soon as possible.”
He added that patients should consider if they can be helped at their local pharmacy, GP or urgent care centre before attending A&E.
Meanwhile, nationally, emergency department waiting times performance hit a record low in October.
Across England, just 83.6% of patients were seen within four hours against the 95% target.
It is the worst performance since records began in 2004, with the national standard last met in July 2015.
A total of 2,170,510 people attended emergency departments last month, an increase of 4.4% on the same time last year.
NHS England said hospitals were under pressure and dealing with “older and sicker patients”.