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If you have diabetes, checking your blood glucose level is probably a big part of your health care routine. After all, keeping your blood glucose levels in your target range is an important step in managing your diabetes. Checking your glucose levels generally still means jabbing a fingertip to get a blood sample. But a lot has changed, and devices have become more user-friendly and high-tech.

Although there are many different brands and models, the devices available to check your glucose generally fall into two categories. The first is a called a glucometer. The second is called a CGM, or continuous glucose monitor. Which one you choose is a matter of cost, comfort, and your health care team’s recommendation. Here’s what you need to know if you are considering a switch or are new to glucose monitoring. Remember, glucose monitoring is one of the most important parts of self-care when it comes to managing your diabetes.

Glucometer and CGM Basics

Many people with diabetes regularly check their glucose levels with a fingerstick blood check and a trusty blood glucose meter. This fingerstick reading will give you a measurement of your glucose level at the moment when you checked it. But many people also check many times a day. Those combined readings will give you a much bigger picture of how well you are managing your glucose levels.

CGMs take the process of tracking your blood glucose to a whole new level. Instead of measuring glucose levels in your blood, they measure them in the fluid underneath your skin. You use an applicator to place a tiny sensor under the skin of your belly or arm. It stays in place with a piece of tape.

Although there are differences among models, most of them send the data from your readings to a receiver that’s similar to a cellphone. Some can send it to a smartphone app or directly to an insulin pump if you wear one. You can even download your data to your computer.

How Accurate Is a CGM Compared to a Blood Glucose Meter?

If you’re testing your blood glucose levels, accuracy is no doubt one of your main concerns.  Blood glucose meters made in the U.S. must meet strict standards set by the FDA. According to the FDA, glucose meter readings are 95% accurate within 15% for all readings within the “usable” blood glucose range and 99% accurate within 20% for all readings within that usable range. The word “usable” means the range of blood glucose values where the meter has proven to be accurate. The bottom line is that fingerstick testing still gives the most accurate results of your glucose level.

Many things can affect the accuracy of your CGM reading, including how your device is calibrated, its sensor chemistry, and your own body chemistry. Confirm your reading with a fingerstick before making changes to your diabetes treatment plan.

What Are the Pros and Cons of Blood Glucose Meters?

Blood glucose meters are generally accurate and easy to use. But like any piece of technology, many things can affect them. For example, you could have problems with your test strips if you don’t store them properly. And your device and test strips could malfunction if you expose them to extreme temperatures. Dirt, alcohol, or other substances on your skin could also affect readings. And just like your TV remote, you need make sure your batteries have enough juice.

Also, pricking your finger isn’t fun. But you can ask your diabetes care team for tips to reduce the potential “ouch.” There are also devices called alternative site glucometers that allow you to prick another body part like your arm or thigh. But they aren’t as accurate as a trusty finger prick.

Despite these downsides, fingerstick testing gives the most accurate results of your glucose level.

What Are the Pros and Cons of a CGM?

You will get expert instruction on how to use your device comfortably and safely. But it does take some time to feel comfortable with the technical aspects of these devices. For example, you’ll need to learn how to insert your sensor, transfer data, and set alarms.

There are some real pluses to using one of these devices. The data you get can help you and your provider see the “big picture” of how well you are managing your glucose over time. It can also show you things that could be affecting changes in your levels. That could translate to more personalized care because your provider can look for trends and patterns.

Most of these devices can alert you if your blood glucose gets too high or too low. That means you can make changes very quickly to keep a minor problem from turning into a major problem.  Plus, a CGM really does reduce the amount of fingerstick testing you do.

What About Insurance Coverage?

Insurance coverage for a glucometer can get a little tricky. If you have private insurance, make sure you check with your insurance company to see exactly what it covers. Some insurers may pay only for specific models, so yours may not pay for the one you want. Insurers may also limit the number of test strips they’ll pay for in a certain time period. If you’re enrolled in Part B Medicare, it will cover test strips and other self-testing supplies, but there are stipulations on brands and where you can buy supplies. There are also limits on the number of test strips it will cover in a certain time frame.

Medicare also covers CGMs. Your out-of-pocket expense depends on your specific plan, where you buy the device, and other things. CGMSs aren’t cheap, but more private insurers are covering them, too. Remember that you’ll also have to replace sensors regularly, which can also add to the cost.

Your best bet is to talk to your insurance company to see exactly what’s covered for the blood glucose monitoring system you choose.

Show Sources

Photo Credit: Daria Nipot / Getty Images

SOURCES:

Diabetes Technology and Therapeutics: “Continuous Glucose Monitoring: A Review of Successes, Challenges, and Opportunities.”

Cleveland Clinic: “Continuous Glucose Monitoring.”

Mayo Clinic: “Blood glucose monitors: What factors affect accuracy?” “Blood Glucose Meters: How to Choose.”

diatribe.org: “Taking the Sting Out of Fingersticks: Lancets, Life Hacks and More.”

Medicare.org: “Does Medicare Cover Test Strips?”

American Diabetes Association: “New Medicare Coverage Requirements Make CGMs More Accessible.”

beyondtype2.org: “How Accurate Are Blood Glucose Meters?”

Juvenile Diabetes Research Foundation UK: “How accurate is my glucose monitor?”

Journal of Diabetes Science and Technology: “Measures of Accuracy for Continuous Glucose Monitoring and Blood Glucose Monitoring Devices.”

National Institute of Diabetes and Digestive and Kidney Diseases: “Continuous Glucose Monitoring.”