Results Summary

What was the research about?

Type 2 diabetes is a long-term illness that causes blood sugar levels to rise. Keeping blood sugar levels normal can help prevent damage to the heart, brain, eyes, limbs, and kidneys. To reduce the risk for type 2 diabetes, people can eat healthy foods and reduce body fat by being active. American Indian and Alaska Native, or AIAN, adults are at high risk for type 2 diabetes. AIAN adults also are more likely than adults of other racial or ethnic groups to have mental health problems, such as depression and anxiety, which can make it hard to prevent diabetes.

In this study, the research team developed and tested a diabetes prevention program for AIAN adults that also addressed mental health. The team compared the new program with a standard program. Both were tailored to address the health needs of AIAN adults. Both involved 16 60- to 90-minute weekly group education sessions led by a trained health coach on diet, physical activity, and weight loss. The new program also included three ways to help people feel connected to others and improve mental health:

  • Group discussions called talking circles, which promote social support
  • Photography and photo review sessions to find the causes of health problems
  • Sessions to share life stories that the team could post on social media

The research team looked at whether the new program reduced body mass index, or BMI, which measures body fat based on height and weight.

What were the results?

After one year, the new program wasn’t better than the standard program at improving

  • BMI
  • Quality of life
  • Healthy eating
  • How active people were
  • Depression
  • Confidence

In both programs, however, people who had more education sessions had larger reductions in BMI than those who had fewer sessions.

Who was in the study?

The study included 205 AIAN adults living in an urban area in California. Of these, 54 percent were also Hispanic. The average age was 52, and 79 percent were women. All were at high risk for getting type 2 diabetes based on their BMI, cholesterol, blood pressure, or blood sugar.

What did the research team do?

The research team assigned people by chance to either the new or the standard program. The team checked BMI before and after the study. People also took a survey before the study started and again 6 and 12 months later. The survey asked about quality of life, healthy eating and exercise, depression, and confidence.

AIAN adults, caregivers, and health professionals helped the research team design the study and recruit people to take part in it.

What were the limits of the study?

This study took place in one city. Results may differ in other places or for AIAN adults living on reservations. Of those in the new program, 18 percent went to all talking circles, 36 percent went to all photo review sessions, and only one person went to both sessions for sharing life stories. Results may differ if more people went to all parts of the new program.

Future studies could explore other ways to prevent type 2 diabetes for AIAN adults.

How can people use the results?

Doctors, nurses, and community partners can use the results of this study when considering ways to prevent type 2 diabetes among AIAN adults.

Final Research Report

View this project's final research report.

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 assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot 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 descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers asked for a more detailed description of how the researchers concealed from the staff what participants’ assignments to study arms were. The researchers added some text to their paragraph on randomization and blinding. The researchers blinded the outcome assessors and the statistician performing data analysis. However, the researchers reiterated that the statistician who assigned participants to the two study arms was not blinded.
  • The reviewers noted that the measure of mental health quality of life was not included in some of the analyses and results, despite the report’s assertion that the enhanced intervention would address some mental health and psychosocial stressors. The researchers added the results of this measure to the text and some figures, stating that the mental health measure did not change significantly at either follow-up time point in either treatment group.
  • The reviewers asked that outcomes be reported as prespecified in the protocol, with body mass index (BMI) the primary outcome, instead of BMI and quality of life reported as dual primary outcomes. The researchers revised their manuscript throughout to report BMI as the primary outcome and quality of life as a secondary outcome, consistent with their protocol.
  • The reviewers noted that the report indicated that discussion of generalizability should await future research with more positive results. The reviewers disagreed, noting that nonsignificant results are also important for generalizability and knowing what does and does not work in studies. The researchers revised this section in their discussion, noting that study results would likely generalize to other urban indigenous groups in the United States, especially California.

Conflict of Interest Disclosures

Project Information

Randall Scott Stafford, MD, PhD
Stanford University School of Medicine
A Patient-Centered Strategy for Improving Diabetes Prevention in Urban American Indians

Key Dates

December 2013
March 2019

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: March 14, 2024