Rationale, design, and sample characteristics of a practical randomized trial to assess a weight loss intervention for low-income women: the Weight-Wise II Program

Obesity is common among low-income mid-life women, yet most published weight loss studies have not focused on this population and have been highly resourced efficacy trials. Thus, practical type 2 translational studies are needed to evaluate weight loss interventions for low-income women. In this paper, we present the rationale, study design, and baseline characteristics of a type 2 translational study that evaluates both the processes and outcomes of a weight loss intervention for low-income women given at 6 county health departments in North Carolina. Key features of this study include random selection of study sites, intervention delivery by current staff at study sites, efforts to integrate the intervention with local community resources, a focus on evaluating the processes of translation using the RE-AIM framework, use of an evidence-based weight loss intervention, a detailed description of participant recruitment and representativeness, and a practical randomized trial designed to assess the effectiveness of the intervention. Of 81 health departments invited to participate, 30 (37%) were eligible and willing, and 6 were selected at random to deliver the intervention. Of 432 potential participants screened by phone, 213 (49%) were eligible and of these, 189 (89%) completed baseline measures and were randomized to receive a 5-month weight loss intervention or a delayed intervention. The mean age was 51, mean BMI 37 kg/m(2), 53% were African American, and 43% had no health insurance. The results of this study should be informative to key stakeholders interested in real world weight loss interventions for low-income mid-life women.