Health departments most commonly cited inadequate target population size as the reason that they were not eligible (). The most common reasons that health departments were not interested in participating were too many competing demands, self-assessed inadequate resources or capacity for program implementation, and self-assessed inadequate staffing.
From 30 eligible and interested sites, we calculated 593,775 possible combinations of samples of 6 sites (30!/[30 − 6]!/6!) (14
). After applying the 7 criteria, 15,177 combinations were considered optimal and retained in the sampling frame, approximately 3% of the original possible combinations (). The most limiting criterion was having no more than 1 county 150 miles away. The least limiting criterion was requiring no more than 1 county in a health district.
Number and Percentage of Site Combinations Meeting Individual and Combined Criteria of 593,775 Possible Combinations
Differences between departments by eligibility, interest, and selection for the study were generally small (). Not interested and not eligible sites were closer to Chapel Hill than were interested sites and nonresponders. Interested sites had larger populations on average than did the other groups. The mean percentage minority population was lower in nonresponders than in the other groups. However, the mean per capita income, percentage below poverty, and percentage enrolled in Medicaid varied minimally across groups. Nonresponding health departments were less likely to participate in the North Carolina Breast and Cervical Cancer Control Program or WISEWOMAN. These health departments also had smaller staffs on average and the smallest average county population.
Characteristics of Health Departments by Eligibility, Interest, and Selection Status for Randomized Trial
The 6 selected sites' characteristics varied minimally from the 30 total sites that were eligible and interested (). The mean distance from Chapel Hill was shorter for selected sites than overall. The mean county population was also less, as was the mean number of health department staff. The staff positions were similar, with the exception that fewer of the selected sites had a registered dietitian. The mean percentage minority, per capita income, and percentage enrolled in Medicaid were similar between the groups.
Most of the selected sites (n = 5) offered patient education in diabetes, hypertension, and cholesterol in a group format. Additionally, most of the selected sites (n = 5) offered some type of adult weight management program, through either individual (n = 5) or group-based counseling (n = 4). Three sites reported collaborating or partnering with another agency to provide adult weight management services. Collaborating agencies included the Expanded Food and Nutrition Education Program (n = 5), faith-based organizations (n = 4), other state or local government agencies (n = 4), businesses (n = 3), employee groups (n = 3), hospitals or medical centers (n = 1), community health centers or clinics (n = 1), and YMCA/YWCA (n = 1).
All 6 interventionists had bachelor's degrees or higher. Half of the interventionists had substantial experience working in public health (). Similarly, the interventionists had been employed at their respective health departments for different periods: 3 were established (14-20 y), and 3 were new (1-3 y). Only 1 had received special training in adult weight management, although 4 had developed, implemented, or evaluated a weight management intervention. One-third had not been involved in a weight management program previously. Most had worked with the target population, low-income women aged 40 to 64 years, through health screening programs, minority health activities, or women's health promotion activities.
Interventionist Characteristics and Ratings of Training Topics
Interventionists were also asked to rate training topics. Topics that were rated most important included behavior change principles, weight management counseling, weight management program development, and community organization and mobilization. Least important topics included body mass index measurement and general physical activity and weight management recommendations and guidelines for adults. The most salient perceived barrier to implementing a weight management program at their respective sites was a lack of client interest (reported by 5 interventionists).