Results Summary

What was the research about?

With type 2 diabetes, a person’s blood sugar levels become higher than normal because the body doesn’t make or use the hormone insulin correctly. Keeping blood sugar levels normal can help prevent health problems that affect the heart, brain, eyes, limbs, and kidneys. Many people with type 2 diabetes use diet, exercise, and medicine to manage their blood sugar levels. They may also prick their fingers and measure their blood sugar levels with personal monitors daily. People can then adjust their diets and exercise in response to the blood sugar levels. But checking takes time, the supplies can be costly, and the health benefits are not clear.

This study focused on people with type 2 diabetes who don’t take insulin. The study compared people who did and didn’t check their blood sugar levels daily to see which group did a better job keeping their blood sugar at good levels. The study looked at what happened if patients who checked their blood sugar levels also received text messages explaining their blood sugar levels. The study also looked at the effects of checking blood sugar levels daily on the people’s quality of life.

What were the results?

At the end of the one-year study, there were no differences, on average, in blood sugar levels and quality of life between people who checked their blood sugar daily and those who didn’t. People who tested their blood sugar levels daily had slightly lower blood sugar levels in the middle of the study than those who didn’t test. But this difference didn’t last until the end of the study. Among people who checked their blood sugar levels, there were no differences in blood sugar levels or quality of life between those who did and didn’t receive text messages.

Who was in the study?

The study included 450 people with type 2 diabetes in North Carolina. The people in the study were 31 to 92 years old. They didn’t take insulin, but most of them took other medicine, such as metformin or a sulphonylurea, to treat their diabetes.

What did the research team do?

The research team assigned people with type 2 diabetes to one of three study groups by chance. People in one group didn’t check their own blood sugar levels for a year. People in the other two groups checked their own blood sugar levels daily. People in both of these groups received their blood sugar level results right away. People in one of the blood sugar testing groups also got text messages with information about what their levels may mean.

The research team took the people’s blood at the start of the study and again a year later. They did a test to measure A1C in the blood samples. This test shows a person’s average blood sugar levels during the past three months. Doctors and patients use the A1C test to find out if people are managing their diabetes well. The research team looked at people’s health records to see their A1C levels between the beginning and the end of the study. The team also surveyed people about their quality of life at the start and the end of the study. The research team compared the results of the A1C test and the survey among the three groups.

What were the limits of the study?

The study didn’t have enough people from different races and ages to find out if blood sugar level testing may help manage blood sugar levels in specific groups of people. The study included people only from North Carolina. The results may be different for people from other places. People in the study didn’t always test their blood sugar levels exactly as instructed by the research team. Results may be different if people tested their blood sugar levels every day as instructed. Doctors didn’t always review the results of the blood sugar level tests or give advice about the results.

Future research could look at whether interaction, such as texting, between doctors and patients with type 2 diabetes about patients’ blood sugar level results improves patients’ blood sugar levels or quality of life.

How can people use the results?

People with type 2 diabetes who don’t use insulin can use these results to ask their doctors if they should check their blood sugar levels daily. Checking blood sugar levels daily didn’t help people in this study manage their blood sugar levels better than those who didn’t. But blood sugar level testing may be useful in some situations, such as before or after a change in diabetes medicine or to inform treatment decisions.

Final Research Report

View this project's final research report.

More to Explore...

Blogs

Monitor Trial Spotlighted in Prominent Blog
Aaron Carroll of the New York Times' "The Upshot" blog — who moderated a 2018 PCORI Annual Meeting plenary session about balancing benefits and potential harms of different treatment options — discussed this study's finding that routine glucose monitoring may be unnecessary for people with Type 2 diabetes who are not on insulin. Study Principal Investigator Katrina Donahue, MD, MPH, was a presenter/panelist in that session.

Study Protocol

View this project's study protocol.

Evidence for Decisions

Blood Sugar Testing to Manage Type 2 Diabetes in Patients Who Don't Need Insulin
It’s important for people with type 2 diabetes to keep their blood sugar at a healthy level. Many patients check their blood sugar at home each day. But checking your blood sugar daily may not help you to manage your type 2 diabetes. This study found that people with type 2 diabetes who don’t use insulin did not benefit from daily self-testing.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also confirms that the research has followed PCORI’s Methodology Standards. During peer review, experts who were not members of the research team read a draft report of the research. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. Reviewers do not have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve how the research team analyzed its results or reported its conclusions. Learn more about PCORI’s peer review process here.

In response to peer review, the PI made changes including

  • Adding more information about what the outcomes of the study were designed to measure and what difference in results between groups would be considered clinically meaningful
  • Expanding the text in places to demonstrate adherence to PCORI Methodology Standards
  • Providing examples of the tailored messages sent to patients who were being counseled about diabetes management without needing to test their blood glucose
  • Adding a discussion of possible reasons for the failure to sustain significant improvements in glycemic control seen in the intervention group at six months
  • Providing the context for their exploratory analyses of the association between hemoglobin A1c and compliance with self-monitoring of blood glucose

Conflict of Interest Disclosures

Project Information

Katrina Donahue, MD, MPH
University of North Carolina Chapel Hill
$2,112,206
10.25302/3.2018.CE.12114980
Effect of Glucose Monitoring on Patient and Provider Outcomes in Non-Insulin Treated Diabetes

Key Dates

May 2013
November 2017
2013
2018

Study Registration Information

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Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
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Last updated: November 30, 2022