Quantitative Interval Variability Index (QIVI) for Serum/Plasma
This test measures how much your blood test results fluctuate over time, which can help assess how stable your health measurements are.
["Understanding how consistently your lab results change can help doctors track long-term health trends."]
Key facts at a glance
- LOINC
- 18543-9
- Short code
- Q-T interval L-V6
- Synonyms
- Q-T interval L-V6
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ekg
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Is the QIVI Index Used For?
The QIVI Index is primarily used to evaluate the variability of specific blood measurements over time. It helps identify whether your lab results are stable or if they change unpredictably, which can be important for conditions requiring consistent monitoring (e.g., diabetes, thyroid disorders).
How Is This Test Performed?
This test involves collecting blood samples at multiple time points (typically over several weeks or months) and analyzing the consistency of your lab results. Your healthcare provider will determine the appropriate timing and frequency based on your medical needs. The blood is usually drawn from a vein in your arm and processed into serum or plasma for testing.
Why Might You Need This Test?
You may need a QIVI Index test if your doctor suspects that your lab results are unstable, which could affect treatment decisions or management of chronic conditions. It’s also used in research or clinical trials to assess variability in study participants’ health markers.
What Does a QIVI Index Result Mean?
A QIVI Index result doesn’t provide a single numeric value like traditional lab tests, but rather a qualitative assessment of variability. High variability may indicate underlying issues like stress, medication effects, or metabolic changes, while low variability suggests stable health measurements. Your doctor will interpret the results in the context of your overall health and medical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
QIVI Index
Frequently asked questions
How often will I need to have this test?
What are the possible risks or side effects of this test?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy