More than 38,000 people - including around 11,000 aged over-75 - spent at least 24 hours in an emergency department (ED) in the first nine months of this year.
New provisional HSE data showed that, of the 38,253 occasions where patients were left in an ED for a day or more, three-in-four (29,043) went on to be admitted for further care.
In terms of patients spending more than 24 hours in an ED, Our Lady of Lourdes Hospital in Drogheda recorded the most in this period, with 3,552 people experiencing long waiting times between January 1 and October 5.
In Galway University Hospital patients had similar long ED stays on 2,797 occasions.
Other hospitals with significantly high numbers of 24-hour ED breaches included University Hospital Limerick (2,673), Tallaght University Hospital (2,622) and Dublin's St Vincent's Hospital (2,576).
In contrast, University Hospital Waterford had no patient stay more than 24 hours in its ED, while Midland Regional Hospital Tullamore had just one 24-hour breach.
Meanwhile, of the 183,098 ED visits made by people aged 75 or older in the first three quarters of this year, 39.8 per cent resulted in the patient waiting nine hours or longer before being admitted or discharged.
Drogheda had the highest rate of older persons' delays, with 64.1 per cent of over-75s spending more than nine hours in its ED. In contrast, in St Luke's Hospital in Kilkenny just 15.5 per cent of patients over 75 stayed nine hours or more in its ED.
The median time a patient spent in an ED in Ireland in the first nine months of the year was 5.76 hours. Duration times in EDs were longest in Beaumont, where patients spent a median time of 8.5 hours in its emergency setting.
In Tallaght, median ED duration was 7.9 hours, while in Naas it was 6.6 hours. This contrasts to 3.1 hours in St Luke's in Kilkenny.
Unsurprisingly, older patients who attended the ED were far more likely to be admitted for follow-on care. People aged 75 and over accounted for just over 93,000 admissions in the first nine months of this year, representing a conversion rate (the percentage of attending patients who were admitted) of 51 per cent.
Among the age group, UHL had the highest number of admissions, at 6,206, over 950 more than in the same period last year. UHL was followed by CUH with 5,480 admissions and St Vincent's at 4,992.
However, in terms of overall ED visits among over-75s, St Vincent's Hospital in Dublin has the most, with 13,231 attendances recorded, an increase of eight per cent on the same period last year.
The number of older patients visiting UHL's ED in the first nine months of 2025 was 11,653, up 18 per cent on 2024.
Almost two-in-three older people (64.6 per cent) who presented to St Luke's in Kilkenny went on to be admitted, the highest conversion rate for this cohort in the country. Following St Luke's was Cavan General Hospital with a conversion rate of 62.2 per cent, while Mayo University Hospital has a 61.1 per cent rate.