The Health Information and Quality Authority has said there are excessive and unsafe waiting times for some referrals for hospital outpatient services.
It says that the management of patient referrals is poor, waiting times for some services can be up to four or five years and there are serious safety concerns.
In a 117-page report 'Patient referrals from General Practice to Outpatient and Radiology Services', HIQA says waiting lists are incomplete and inaccurate and the information is not up-to-date.
The review says that patients should not wait more than 90 days to be seen for an outpatient referral, yet only a very small number of hospitals achieve this target.
Data for November 2010 found that six of 22 hospitals that supplied information met the target.
There is no national agreement on the information that should be included in patient referral letters sent from GPs to hospitals, leading to a risk that critical information will be omitted from the letter.
The report says that there is a lack of accurate, complete and comparable information about patient referrals and patients cannot be assured of timely access to services.
There are problems for both GPs and patients in contacting hospitals with queries relating to individual referrals, it says.
HIQA says Ireland is far short of best international practice in handling patient referrals and the situation could be dramatically improved with changes to procedures and practices, which do not involve significant expenditure.
More than 3.3m people are seen at consultant-led outpatient clinics each year, of which around 900,000 are first-time appointments.
The report makes 26 recommendations. It says that the HSE should have a clear patient referral system for outpatient and diagnostic radiological services and that referrals should be individually and collectively tracked.
HIQA in cooperation with the Irish College of GPs has developed a standard template for use in patient referrals.
The Health Service Executive says it is working closely with hospitals to implement the recommendations of the HIQA report on referrals to outpatient clinics.
It said that pilot projects were also under way in facilities in Cork, Kerry and Tallaght in Dublin.
Dr Joe Clarke, HSE National Primary Care Clinical Director, said that an electronic system was being put in place to allow GPs make direct electronic referrals from their practice.
The Executive is also working with the Irish College of GPs on a standard national referral letter.