VIC Privacy of pathology test results - right to delete

[Tim W]

Does Australia Privacy Principle 11 not give me a basis to request this though, in a way that has a legal basis?

No

...am I misinterpreting that it requires organisations to remove information about me once they no longer require it (which I'd guess could be interpreted as them no longer providing me with the service for which I gave them the information).

Yes

If I am misinterpreting it, is this not how it works at all, or is the case of pathology labs a special case?

There is a statutory regime around medical records, labortatory records, and diagnostic materials. In may cases, that's where the seven years requirement comes from. In some cases, it's ten years.