NC-BCSP was evaluated using a nonrandomized community trial that took place in eastern North Carolina in five intervention communities and five comparison communities, geographically separated by Pamlico Sound. The two sets of counties had similar demographic, geographic, and cultural characteristics, as well as similar access to health care and mammography services. Two-thirds of the counties' adult residents lived in rural areas or small towns with populations below 5,000. Thirty-seven percent of the community members were non-White, and 12% lived below the poverty line.
Two cohorts of African American women were chosen by using a systematic random sample to select census blocks from each county. Interviewers canvassed door-to-door in 520 selected blocks and approached 2,355 households. Of these, 2,120 households with at least 1 woman who was 50 years or older and did not have breast cancer agreed to participate. A random selection was then made from among these eligible households. A total of 494 women in the intervention group and 499 women in the comparison group were interviewed at baseline. Baseline data were collected in 1993-1994.
The intervention communities received NC-BCSP, while the comparison communities did not receive any intervention. However, the Centers for Disease Control and Prevention's Breast and Cervical Cancer Control Program, which funds mammograms for eligible low-income women, became available in all 10 counties 1 year after initiation of NC-BCSP.
Follow-up data collection took place in 1996-1997 and included 390 intervention women and 411 comparison participants. At both baseline and follow-up, trained female interviewers recruited from the community administered a 45-minute questionnaire in women's homes. In most cases, the 58 interviewers were matched in age and race to the women being interviewed. The baseline and initial follow-up interviews were conducted an average of 32 months apart for the intervention cohort (range 20-47 months) and 30 months apart for the comparison cohort (range 18-41 months).