The HSE has published an online interactive database showing hospital outpatient activity for the public and GPs to view, as well as health managers and staff.
It shows hospital outpatient attendance on a hospital-by-hospital and specialty-by-speciality basis and will be updated monthly.
The website covers 21 acute hospitals and more are due to be added over the coming months.
The HSE said the data will be updated monthly and will be used to increase outpatient activity and reduce outpatient waiting times, to monitor the average number of outpatient appointments.
It said it will also help it improve performance and patient access and to provide information to the Department of Health.
The datasets show variations between hospitals and are aimed at assisting teams across the health service see and understand how they are performing compared to other comparable hospitals.
The Department of Health said the HSE data website launched today shows significant variations in the average number of outpatients being seen by consultants, in the same specialty.
It also said the data shows a big reduction in the overall number of outpatients being seen per patient-facing consultant.
The HSE has noted that the outpatient data has limitations, as sometimes this activity may not be correctly accredited, due to differences at each hospital in how they record medical specialties and sub-specialties.
Meanwhile, national outpatient waiting list numbers are reducing.
The most recent national outpatient waiting list shows more than 593,000 patients waiting in May to be seen by a consultant at an outpatient clinic for the first time.
This compares with more than 600,800 in May last year and more than 624,000 patients the previous year.
Comparing hospitals poses challenges due to a variety of complex factors such as different funding levels, demographics, staffing levels and vacant posts, the number of beds open, the patient case mix, the complexity of cases seen and if a hospital is a national specialist centre for referrals.
Professor Matthew Sadlier, Chairperson of the Irish Medical Organisation's Consultants' Committee, said that while the union welcomed the publication of the productivity data today, it was important to note that the kind of blanket approach of comparing hospital sites is of little value in terms of understanding what is happening at individual hospital level.
The Irish Patients Association said that there may be many barriers to optimum performance by hospitals.
Stephen McMahon, Director of the IPA, said the recent allocation of an additional €1.5 billion increase in funding this week to address overruns in the health system for 2024 was an example.
