Study of emotional distress in a comparative effectiveness trial of diabetes treatments: Rationale and design.

Emotional distress, including depression and diabetes-specific distress (e.g., feeling overwhelmed by living with diabetes, feelings of failure related to diabetes self-care), is a significant and prevalent problem for patients with type 2 diabetes. Both depression and diabetes distress have been associated with metabolic/glycemic control, diabetes complications, mortality, and quality of life. Recent findings further suggest that risk for emotional distress is influenced by diabetes treatment. The GRADE Study (Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study) is generating prospective data that will provide a unique opportunity to examine the relationships between emotional distress, diabetes treatment, and outcomes in an experimental design. The GRADE study is a randomized clinical trial that will compare the metabolic effects of four common anti-hyperglycemic drugs when combined with metformin. This sub-study recruited a subset (n = 1739) of GRADE participants and will examine patient-level variation in baseline emotional distress as a predictor of glycemic control and other health outcomes, independent of treatment effects. The study will also provide an experimental examination of treatment regimen effects on emotional distress over time as part of the overall evaluation of comparative effectiveness. Evaluation of emotional distress using validated measures will allow us to disentangle the roles of depressive symptoms and diabetes distress, factors that share significant overlap but require distinct approaches to screening and treatment. Study findings may directly influence practice decisions regarding screening and treatment for emotional distress as part of diabetes care. ClinicalTrials.gov Identifier: NCT01794143.