1. Harmonised intervals: the same everywhere

The Australasian Association for Clinical Biochemistry and the Royal College of Pathologists of Australasia ran a harmonisation programme that agreed common adult reference intervals for a first panel of routine chemistry analytes. An initial group of twelve was endorsed in 2014 — including sodium, potassium, chloride, bicarbonate, creatinine, calcium, phosphate, magnesium, lactate dehydrogenase, alkaline phosphatase and total protein — followed by a second group covering total bilirubin, creatine kinase, ALT, AST, GGT and lipase.

Where an interval is harmonised, Vector publishes it on the marker page and says so plainly. Those are the numbers that do not change between providers.

See which markers carry a published interval

2. Everything else: the laboratory's interval governs

Most of the 82 markers Vector tracks are not part of the harmonised set. Ferritin, TSH, free T4, the lipids and the sex hormones remain candidates for harmonisation rather than harmonised, and their intervals genuinely do differ between laboratories, assay methods and reference populations.

For those markers Vector does not publish a number, because a number from a website would be actively misleading against a result from a laboratory that used a different assay. The marker pages say so, and point you back to the interval printed beside your own result.

3. Guidance is not the same as a reference interval

Professional guidance may set a decision threshold — a level at which something should be investigated or treated — and that is a different object from a reference interval, which simply describes the central range of a reference population. A result can sit inside the interval and still be above a guidance threshold, and the reverse also happens. Age, sex, pregnancy, medicines and symptoms all bear on which one is relevant.

4. Comparing your own results over time

  • Keep the unit and the collection date with every value.
  • Compare the same marker, and where possible results from the same laboratory and method.
  • Record fasting status, recent illness, exercise, medicines and relevant reproductive context.
  • Treat one out-of-range result as a prompt to repeat or ask, not as a finding.
  • Raise persistent or unexpected changes with your GP or treating clinician.

This is exactly the comparison Vector is built to make easier: it keeps the value, the unit, the date and the interval together so the next report has something honest to be read against. See how tracking works.

Sources

  1. AACB / RCPA Common Reference IntervalsHarmonised adult reference intervals endorsed for Australian and New Zealand laboratories.
  2. RCPA Manual: Pathology TestsAustralian pathology reference for individual tests and result context.