Design and methods of NYC care calls: An effectiveness trial of telephone-delivered type 2 diabetes self-management support

Although problems with type 2 diabetes (T2D) self-management and treatment adherence often co-occur with emotional distress, few translatable intervention approaches are available that can target these related problems in primary care practice settings. The New York City (NYC) Care Calls study is a randomized controlled trial that tests the effectiveness of structured support for diabetes self-management and distress management, delivered via telephone by health educators, in improving glycemic control, self-management and emotional well-being among predominantly ethnic minority and socioeconomically disadvantaged adults with suboptimally controlled T2D. English- and Spanish-speaking adults treated for T2D in NYC primary care practices were recruited based on having an A1C ≥ 7.5% despite being prescribed medications for diabetes. Participants (N = 812) were randomly assigned to a telephonic intervention condition with a stepped protocol of 6-12 phone calls over 1 year, delivered by a health educator, or to a comparison condition of enhanced usual care. The primary outcome is change in A1C over one year, measured at baseline and again approximately 6- and 12-months later. Secondary outcomes measured on the same schedule include blood pressure, patient-reported emotional distress, treatment adherence and self-management behaviors. A comprehensive effectiveness evaluation is guided by the RE-AIM framework (Reach, Effectiveness, Adoption, Implementation, Maintenance) to gather data that can inform dissemination and implementation of the intervention, if successful. This paper describes the study rationale, trial design, and methodology.