What the Alzheimer’s requisition is for
It orders LifeLabs’ plasma tests for Alzheimer’s disease: the combined amyloid 42/40 and p-tau217 evaluation, the amyloid 42/40 ratio, p-tau217, p-tau181, ApoE isoform, neurofilament light chain (NfL), and GFAP. LifeLabs describes p-tau217 as a diagnostic biomarker and the amyloid ratio as a test that complements symptom assessment. These results support a cognitive assessment and don’t replace it. LifeLabs publishes a separate requisition for British Columbia.
Who completes it
An authorized ordering healthcare practitioner completes the patient and practitioner sections, ticks the tests, and signs. Collection staff fill in the collection details.
How to fill in the requisition
Patient and practitioner details
Patient name, date of birth, sex, address, phone and health card number, then your name, address and number, and anyone to copy on the report. Add a diagnosis or comment, such as the cognitive findings that prompted testing.
Test selection
Tick each test you want. The combined evaluation already includes the amyloid 42/40 ratio and p-tau217, so ticking them separately duplicates the order. ApoE is a genetic risk test, and LifeLabs offers genetic counselling after ApoE results.
Biotin and collection
Tell the patient to stop biotin at least 72 hours before the draw for the starred tests. The patient must attend a LifeLabs patient service centre in person.
Signature
Sign and date the requisition.
Common reasons it’s delayed
- Other tests added, which the lab won’t run on this form.
- Biotin taken within 72 hours of a starred test.
- No test ticked, or the combined evaluation and its parts ticked together.
- A patient outside Ontario using the Ontario form.
- Missing practitioner signature.
Submitting and who pays
The patient takes the requisition to a LifeLabs patient service centre and pays LifeLabs for the tests. The requisition states it is private pay and uninsured.