Despite measures introduced to ease the problem, the number of people having to wait long periods in North Wales emergency departments has risen.
In June, 983 patients had to wait over 12 hours, a rise of 115 on the May figure, with the biggest increase (56) being at Glan Clwyd Hospital.
Meanwhile 79 per cent of patients completed their treatment within four hours, a slight decrease on the May figure, and the greatest deterioration was in Ysbyty Gwynedd.
In a report to the Betsi Cadwaladr University Health Board, the organisation’s head of operations, Morag Olsen, says: “This is disappointing, given the sustained month-on-month improvement over the last six months.
“We are refocusing attention on the importance of ensuring patients move to a destination ward in a timely way and reiterating the risk of harm to patients when they are delayed for long periods in our emergency departments.”
Ms Olsen says that measures introduced last month are now in place.
“The impact of the actions will be monitored throughout this first month,” she says in her report.
“Early indications suggest that some actions are having a positive effect, others not so much, and this will need to be acted on quickly at the end of this month.”
Meanwhile there was an improvement in the number of patients kept waiting for over an hour in ambulances outside the three main hospitals.
A total of 4,588 patients were taken to emergency departments in June and 599 of them had to wait at least 60 minutes.
That followed a slight dip in performance in May.