Back to Ask the Diabetes Team Ask the Diabetes Team

How does a person determine if a home testing system is accurate? We were recently at the hospital where they did a comparison test. At that time the hospital lab gave a reading of 23.2 [mMols/liter]. One of our home meters read 25.2 and the other 24.7. Should this concern us? We bought one meter in March and one in April.


These readings are close enough that they can be considered "the same." In general, you're correct about how to compare meters, but there are technical factors that must be considered in the evaluations.

Potential reasons for the variations that you saw:

  • The home glucose meters are only accurate within about 20% or so.
  • Was the blood drawn at the same time or different times? Blood sugar can change rapidly.
  • Was the blood drawn from the same site? Capillary blood from the finger tip will read differently than blood from a vein puncture.
  • Some meters are designed to read their results in terms of "whole blood" (which contains both red blood cells and liquid serum) and others read in terms of serum. The blood sugar levels in the serum are somewhat higher than those of whole blood; so check whether the meter and the lab were measuring the same thing!


Original posting 11 Jul 96


  Back to Ask the Diabetes Team Return to the Top of This Page

Last Updated: (none)
This Internet site provides information of a general nature and is designed for educational purposes only. If you have any concerns about your own health or the health of your child, you should always consult with a physician or other health care professional.

This site is published by T-1 Today, Inc. (d/b/a Children with Diabetes), a 501c3 not-for-profit organization, which is responsible for its contents. Our mission is to provide education and support to families living with type 1 diabetes.
By using this site, you agree to our Terms of Use, Legal Notice, and Privacy Policy.
© Children with Diabetes, Inc. 1995-2018. Comments and Feedback.