A randomized controlled trial of a shared decision making intervention for diabetes prevention for women with a history of gestational diabetes mellitus: The Gestational diabetes Risk Attenuation for New Diabetes (GRAND study)

Background: Gestational diabetes mellitus (GDM) is a risk factor for the development of type 2 diabetes. Metformin and lifestyle change through a Diabetes Prevention Program (DPP) are equally effective in preventing diabetes in patients with a GDM history, so women can choose a strategy based on their preferences. This study aims to test whether shared decision making (SDM) can help women with a history of GDM increase adoption of evidence-based strategies and lose weight to lower their risk of incident diabetes in real-world settings.

Methods: This pragmatic randomized controlled trial (RCT) will test the effectiveness of SDM for diabetes prevention among 310 overweight/obese women with a history of GDM and prediabetes from two large health care systems (n = 155 from UCLA Health and n = 155 from Intermountain Healthcare). The primary outcome is the proportion of participants who lose ≥5% body weight at 12 months. Secondary outcomes include uptake of DPP and/or metformin and other patient-reported outcomes such as patient activation and health-related quality of life. Rates of GDM in a subsequent pregnancy will be an exploratory outcome. A descriptive analysis of costs related to SDM implementation will also be conducted.

Conclusion: This is the first RCT to examine the effectiveness of SDM on weight loss, lifestyle change and/or metformin use, and other patient-reported outcomes in participants with a GDM history at risk of developing diabetes.

Trial registration: ClinicalTrials.gov, NCT03766256. Registered on 6 December 2018.