Hospital patients faced delays getting treatment last month as accident and emergency departments struggled to cope with demand.
Figures released today show the number of A&E attendances at Mid Yorkshire Hospitals Trust was up by more than 1,800 in December compared to the same month last year.
The trust, which runs Pinderfields, Pontefract and Dewsbury Hospitals, missed its target in each week of last month to see 95 per cent of A&E patients within four hours.
The third week of December was particularly tough as just 80 per cent of A&E patients were seen within four hours.
That week 430 patients waited between four and 12 hours to be seen in A&E, NHS England figures show.
Neil Clark, Mid Yorkshire’s director of operations, said: “It is down to the commitment and hard work of our staff that we remain in the top 30 per cent of all trusts for our A&E performance, despite being the fourth busiest trust in the country.
“We are facing increased demand for our services and we’re asking people to think carefully about whether A&E is really the best place for their condition.
“A&E departments are for life-threatening and emergency conditions, such as heart attacks, strokes, breathing problems and serious accidents.
“We need to make sure that A&E services are free to help the people who really need them.
“Up to one out of every four people who go to A&E could have either self-treated or used an alternative local service, avoiding what can be a stressful visit to hospital.”
A&E departments around the country were hit with increased attendances as GP surgeries closed for Christmas and the non-emergency NHS 111 helpline also struggled to cope with demand.
Performance in the NHS in England was the worst in a decade for meeting the A&E waiting times target.
NHS bosses have appealed for people only to go to A&E in a genuine emergency.
At Mid Yorkshire there were 17,770 attendances at A&E departments last month, an increase of 1,859 on December last year.