The majority of our patients enter the Virta program already owning a blood glucose testing device, and you may find yourself comparing results from your Virta meter with your personal device. Different meter brands have different technologies, and tend to vary in measurements and this variance should not be considered inaccuracy by Virta’s meter. Please see below for detailed accuracy information for both glucose and ketone readings.
Frequently Asked Questions
Can I use the control solution to test for accuracy?
- Yes! The control solution that comes with your meter is intended to be used when you believe your meter is giving inaccurate results. Please visit our detailed article titled, "How and When to use Control Solution".
What questions can I ask to troubleshoot for varying or high glucose results?
- Do you use alcohol to clean the finger or make sure your finger is washed with unscented soap, rinsed well with all soap residue rinsed away and completely dry?
- Are you always wiping away the first droplet of blood (with tissue) and test on the 2nd and/or 3rd droplet?
- Do you NOT squeeze near the prick hole to get enough blood? Squeezing near the prick hole will force out interstitial fluid that skews results.
Should I compare back-to-back results?
- Intuitively, it may seem that comparing back-to-back results from the same glucose or glucose-ketone meter would be a helpful way to determine its accuracy or to receive more accurate readings, but that’s actually not the case.
First, as discussed below in the Accuracy sections of this article, keep in mind that expected variations in readings will occur:
- +/- 15% variation compared to baseline lab results, 95% of the time
- +/- 20% variation compared to baseline lab results, 99% of the time
- Therefore, for example, a repeat reading of a lab-validated glucose sample that’s 100 mg/dL would be expected to range from 85-115 mg/dL with a home glucometer.
- Beyond that, performing back-to-back readings at home further decreases accuracy for these reasons:
- If you use a single sample (blood droplet), prolonged exposure to air skews readings because glucose oxidizes (reacts to oxygen).
- Blood glucose levels can change rapidly in your body, so even samples taken close to one another in time can be different.
- Taking readings using samples from different fingers may result in differences because the glucose content of fluids from different body areas can be different.
How accurate is this meter for ketone readings?
- Like glucose, ketone levels may vary for the reasons discussed above. If you feel you are getting inaccurate ketone readings, you should always perform a control solution test to see if your meter and strips are testing within range. Please visit our detailed article titled, "How and When to use Control Solution.".
Why am I getting the same ketone readings multiple days in a row?
- Ketone levels are slower to change than glucose. It is not uncommon to receive the same ketone reading over multiple days, especially if you are testing at the exact same time every day. We suggest giving yourself a 5-day window to make changes to see if those changes are reflected in your ketone readings, and also try testing at different times of the day over those 5 days. If you go more than 5 days without seeing any difference in your ketone readings, you should perform a control solution test to make sure the strips and meter are working correctly.
What can interfere with my glucose or ketone measurements?
- Here are some of the most common factors that can affect your blood glucose and ketone measurements.
- Strip placement in the meter port and blood fill level. Make sure your strip is firmly placed into the port, and that the blood sample completely fills the channel.
- Hydration! If you are dehydrated or anemic, your results may be less accurate.
- Hygiene and testing protocol. Use the provided alcohol swabs before every test (or wash your hands) and make sure to code sync each new vial of ketone strips.
- Altitude, temperature, and humidity.
- Store test strips between 36-86°F. Store at 10-90% humidity. Avoid heat and direct sunlight. Use the test strips at temperatures between 45.5-113°F.
- Interfering substances. Some substances, such as Tylenol, elevated uric acid, or low glutathione may interfere with your glucose test results.
- Food or contaminants like lotions, exogenous ketones, and MCT oil on the skin or strips (i.e. if strips come into contact with a surface that has a contaminant).
- Exposure to air. Studies have shown that extended exposure of the blood sample to air can result in readings with a 10% variance, as a result of evaporation, coagulation, and changes in a small volume of blood.
- Strip expiration. Use your strips within 6 months of opening the vial.
I still think my meter is inaccurate, what do I do next?
Please visit our support center article to review best practices for taking measurements: How to Test. If these troubleshooting tips have not solved your issue, please contact our support team, here.