The Health Information and Quality Authority has published new referral and treatment guidelines for five scheduled surgical procedures.
HIQA says that across all specialties, 38% of all patients seen in outpatient clinics between 2005 and 2011 were referred back to their GPs without surgery or being sent for further tests.
The procedures involved are surgery for varicose veins, tonsillectomy, grommets, adenoidectomy and cataract surgery and in certain cases relate to surgery for both adults and children.
The agency says the evaluations would see these procedures restricted to patients who may derive limited clinical benefit and as a result free up capacity for other patients.
The new guidelines say that patients with no visible or palpable signs of disease should not be referred.
In relation to cataract surgery, HIQA says that 10%-20% of referrals to an outpatient clinic are not suitable for surgery when first seen.
But it expects the number of cataract surgery cases to increase given the ageing population.
In relation to tonsillectomy, the report says treatment costs around €11m a year.
Up to half of the cases referred for an outpatient appointment are not suitable candidates at the time for surgery.
In the case of varicose vein surgery, the average inpatient case costs €3,810.
HIQA says it does not believe the guidelines will result in a reduction in the overall number of operations, but should minimise referral of patients to outpatient clinics who do not proceed to surgery.
Last October, the HSE asked HIQA to undertake a series of evaluations of scheduled surgical procedures and to advise on possible thresholds on high volume procedures.
The HSE has reported a 22% increase in demand for these procedures in 2011, compared to the previous year.
There are currently an estimated 388,000 patients waiting for a first outpatient appointment and the aim of the new guidelines is to ensure the right patients are referred for the correct treatment at the right time.
According to HIQA, over 3,500 varicose vein surgical procedures are performed each year, 3,500 tonsillectomy cases, 3,400 grommets plus adenoidectomy cases and 9,500 cataract surgery cases.
The new evaluations have been sent to the HSE and the Minister for Health.