This content originally appeared on diaTribe. Republished with permission.
By Laura Brigham
Key takeaways:
At-home A1C tests are a quick and convenient way to measure the average amount of glucose in a person’s blood over the previous 90 days.
At-home A1C tests are less accurate than lab tests but can still be beneficial for diabetes management.
For those who don’t have access to regular in-person care or technology like a continuous glucose monitor, at-home A1C tests can be very useful.
With the explosion of telehealth services over recent years, more and more people are looking for ways to manage their health remotely. That includes using tools like at-home A1C tests.
These tests allow users to skip a trip to the doctor’s office and test their A1C from home. Though convenient and quick, how accurate is an at-home A1C test?
What the research says
One 2022 study found that at-home A1C tests don’t always deliver the same accuracy as laboratory A1C tests. Researchers found large discrepancies in the results of three at-home A1C tests. The Home Access test performed the best, followed by the A1CNow+ test, with the CoreMedica test demonstrating the lowest accuracy.
Although the at-home results weren’t as accurate as the lab tests, testing at home can still be a beneficial part of a diabetes care routine for both healthcare providers and people with diabetes.
“For patients, a blood draw is the best but being able to get the data from an at-home hemoglobin A1C test still has value,” said Dr. Laura Jacobsen, pediatric endocrinologist at the University of Florida and lead researcher on the study.
How A1C tests work
A1C tests have long been the standard measure to evaluate blood sugar levels over time and inform decisions on how to manage blood sugars moving forward.
Simply put, A1C tests measure sugar in your blood. Hemoglobin is a protein inside red blood cells that transports oxygen through the body and gives blood its red color. When blood sugar is high, more sugar binds to hemoglobin, which is reflected in an A1C (or HbA1C) test.
A1C tests are an estimate of the average amount of glucose in the blood. Red blood cells last about three months before being replaced, which is why A1C tests reflect glucose levels for approximately the past 90 days.
Not all tests are created equal
To better understand why accuracy between A1C tests can vary, here’s a look at the different types :
At-home rapid tests. With these tests, you get results in minutes. All you need to do is prick your finger, add your blood sample to the test tray, insert the tray into the reader, and you’re done.
At-home, mail-in tests. The user gets a finger stick blood sample and mails it to a laboratory. Results usually return in a matter of days or weeks.
Office capillary tests. This involves a finger stick test during a visit to a doctor’s office or clinic. A small in-office analyzer provides results, which you usually get during the visit.
Venous blood laboratory tests. A blood sample is drawn from a vein for a more sensitive and accurate laboratory analysis.
Pros and cons of at-home A1C tests
Though testing A1C levels at a medical office or lab provides the most accurate results, they involve an in-person visit with a healthcare provider, which can be inconvenient or uncomfortable for some people. For many people, at-home tests may be the best – and sometimes only – option.
“If you have a patient out in rural America who doesn’t have access to drive to the endocrinologist every three months, we can mail them a kit,” said Jacobsen. “They can do the A1C at home, it still really helps us know if their A1C is 7% or 10% to direct management.”
In other words, some data is much better than no data.
“If we’re talking about a population who’s never been diagnosed, who doesn’t have access to primary care, and we can use the tests just to get a general sense of where someone’s sugars are – there’s huge utility,” said Jasmine Gonzalvo, director of the Center for Health Equity and Innovation at Purdue University.
She added that at-home tests provide a huge opportunity for rural, uninsured, underinsured, immigrant, and non-English speaking populations who may not have access to the health care system.
Still wondering if at-home A1C testing should be part of your diabetes management plan? Let’s weigh the pros and cons.
Pros
Convenience
Privacy
Helps avoid feelings of stigma associated with less-than-perfect test results
Early detection possibly before symptoms
Can help motivate people to better manage their health
Can be less expensive than lab testing for those with limited or no insurance
Cons
Risk of a mistake using the device
Lower accuracy
Risk of misinterpreting results
May not be covered by insurance
A1C vs. CGM and time in range
Continuous glucose monitors (CGM) are wearable devices that continuously monitor glucose levels, providing immediate, actionable data and showing trends in glucose fluctuations.
The continuous measurements from CGMs allow people with diabetes to measure their time in range, which refers to the percentage of time a person’s blood glucose value stays within their target range (typically 70-180 mg/dL). Time in range is a relatively new, but powerful metric for daily diabetes management. Unlike A1C, time in range provides information about daily fluctuations in glucose levels.
“I prefer time in range,” said Jacobsen. “But the big thing for me is that even though a lot of people have CGM, not everyone has it.”
“We still have a lot of people with type 1, especially adults, who can’t get CGM insurance coverage. Many patients with type 2 can’t get a CGM. Until we can get access improved and the cost down, we still need A1C,” she added.
Gonzalvo agreed that CGM data has become the gold standard in diabetes management.
“CGM will give you the wealth of information that you really need,” said Gonzalvo.
Where to get at-home A1C tests
You can easily get an at-home A1C test at a pharmacy or order one online. There are many different brands, but here are some popular options.
At-home, immediate results:
A1CNow
ReliOn A1C Self Test System
CVS At Home A1C Test Kit
Walgreens At-Home A1C Test Kit
At-home, mail to lab:
EverlyWell
LetsGetChecked
myLAB Box
Home Access
DTI Laboratories
For more on A1C and glucose management:
Get to Know Your Lab Tests: A1C, eGFR, UACR, and More
New Oral Drug Leads to Better A1C and Weight Loss
Limitations of A1C: How Does A1C Vary by Race and Ethnicity?