Open Access Open Badges Study protocol

Examining the impact of genetic testing for type 2 diabetes on health behaviors: study protocol for a randomized controlled trial

Corrine I Voils129*, Cynthia J Coffman13, David Edelman12, Matthew L Maciejewski12, Janet M Grubber1, Azita Sadeghpour1, Alex Cho4, Jamiyla McKenzie1, Francoise Blanpain5, Maren Scheuner67, Margarete Sandelowski8, M Patrick Gallagher1, Geoffrey S Ginsburg4 and William S Yancy12

Author Affiliations

1 Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, NC, USA

2 Department of Medicine, Duke University Medical Center, Durham, NC, USA

3 Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC, USA

4 Institute for Genome Sciences & Policy, Duke University Medical Center, Durham, NC, USA

5 Clinical Molecular Diagnostics Laboratory, Duke University Medical Center, Durham, NC, USA

6 Division of Medical Genetics, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA

7 Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA

8 School of Nursing, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA

9 Veterans Affairs Medical Center (152), 508 Fulton St., Durham, NC, 27705, USA

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Trials 2012, 13:121  doi:10.1186/1745-6215-13-121

Published: 1 August 2012



We describe the study design, procedures, and development of the risk counseling protocol used in a randomized controlled trial to evaluate the impact of genetic testing for diabetes mellitus (DM) on psychological, health behavior, and clinical outcomes.


Eligible patients are aged 21 to 65 years with body mass index (BMI) ≥27 kg/m2 and no prior diagnosis of DM. At baseline, conventional DM risk factors are assessed, and blood is drawn for possible genetic testing. Participants are randomized to receive conventional risk counseling for DM with eye disease counseling or with genetic test results. The counseling protocol was pilot tested to identify an acceptable graphical format for conveying risk estimates and match the length of the eye disease to genetic counseling. Risk estimates are presented with a vertical bar graph denoting risk level with colors and descriptors. After receiving either genetic counseling regarding risk for DM or control counseling on eye disease, brief lifestyle counseling for prevention of DM is provided to all participants.


A standardized risk counseling protocol is being used in a randomized trial of 600 participants. Results of this trial will inform policy about whether risk counseling should include genetic counseling.

Trial registration Identifier NCT01060540

Genetic testing; Type II diabetes; Weight loss