The Laboratory Schedule Test List categorises tests into general areas, e.g. chemical pathology, haematology, and then
further categorises the tests into Tier One and Tier Two tests.
A Tier One test can be ordered by any medical practitioner with a current practising certificate in
New Zealand. Tier One tests include the “core” tests requested frequently in primary care, e.g. full blood count,
INR, creatinine and electrolytes, along with many other tests that are only ordered intermittently by General Practitioners.
A separate list has been developed for midwives (see: “Laboratory Schedule Review
A Tier Two test is regarded as a specialist test that can only be ordered by a clinician with “appropriate
vocational registration or credentialing”. It is intended that the ordering of some Tier Two tests is restricted to the
specialists named in the schedule, e.g. a request for sex hormone binding globulin (SHBG) should be from an Endocrinologist,
O&G specialist or Chemical Pathologist. In practice, however, the “rules” are not intended to be unnecessarily restrictive
and any practitioner can order a Tier Two test if they have endorsement or pre-authorisation by a relevant specialist,
or if the test falls within their area of expertise. The clinician requesting the test can also consult with a laboratory
pathologist for advice and approval for the use of the test.
For some tests in each tier a clinical guideline has been developed to direct appropriate use. This is
indicated in the comments section of the Laboratory Schedule Test List with the word “Guideline”. If there are
specific requirements that apply when ordering a test, these are identified within each individual guideline
with the words “Referral criteria available”. The laboratory may query the test if the reason for requesting
it is not within these parameters. Examples of Tier One tests for which a guideline has been developed include
growth hormone, amino acids, faecal calprotectin, T3 and T4 and carcinoembryonic antigen (CEA).
Some tests are categorised as both Tier One and Tier Two and also have supporting information to guide appropriate use.
In some situations a Tier One test can only be ordered if the referral form contains appropriate clinical information,
otherwise the test is regarded as a Tier Two test, and it should be ordered by a specialist as indicated in the schedule.
For example, serum cobalt and serum chromium can be ordered by any medical practitioner if the clinical information provided
states that this test is being used in a patient with a metal-on-metal joint replacement. If this indication is not specified,
then the test is regarded as a Tier Two test and the laboratory may not proceed with the request.
How is the Laboratory Schedule Test List organised?
In the Laboratory Schedule Test List, tests are listed alphabetically, e.g. in the chemical pathology and microbiology
test sections, or are listed in relevant subcategories within a specialty, e.g. coagulation tests within the haematology
section and allergy tests within the immunology section. Approximately 80% of the tests are in the chemical pathology
For each individual test:
- The Tier is indicated
- Specialists who can order the test may be listed for some of the Tier Two tests
- A note in the comments box may indicate if there is a guideline available that restricts or recommends the use of
the test, if there are specific referral criteria for the use of the test or if the test is unfunded and there may be
a charge to the patient
In addition, the microbiology section has an extra column indicating whether the infection being tested for is Notifiable
under the Health Act or the Tuberculosis Act. A number of notes also follow giving more specific advice about notification,
e.g. patients with acute hepatitis B and C (including those with neonatal hepatitis B and documented hepatitis C seroconversion
within 12 months) should have their condition notified to the Medical Officer of Health. Some microbiology tests include
a comment that consultation with a Public Health specialist is indicated. This consultation can fulfil the requirement
for specialist advice prior to ordering of tests.
The genetics section of the schedule varies from the other sections because, due to the rapid increase in the number
of tests now available, it was recognised that these could not all be itemised. The list of genetic tests therefore includes
the most commonly requested tests. The majority of the genetic tests listed are classified as Tier Two tests and in most
situations it is anticipated that General Practitioners will not be ordering these tests. It is recommended that advice
be sought before any genetic tests are requested. Genetic tests usually require prior written consent from patients. In
addition, these tests are often very costly for the laboratory to undertake.