title: Rethinking sources of representative controls for the conduct of case-control studies in minority populations.
abstract: BACKGROUND
  Recruitment of controls remains a challenge in case-control studies and particularly in studies involving minority populations.
  
  
  METHODS
  We compared characteristics of controls recruited through random digit dialing (RDD) to those of community controls enrolled through churches, health events and other outreach sources among women of African ancestry (AA) participating in the Women's Circle of Health Study, a case-control study of breast cancer. Odds ratios and 95% confidence intervals were also computed using unconditional logistic regression to evaluate the impact of including the community controls for selected variables relevant to breast cancer and for which there were significant differences in distribution between the two control groups.
  
  
  RESULTS
  Compared to community controls (n=347), RDD controls (n=207) had more years of education and higher income, lower body mass index, were more likely to have private insurance, and less likely to be single. While the percentage of nulliparous women in the two groups was similar, community controls tended to have more children, have their first child at a younger age, and were less likely to breastfeed their children. Dietary intake was similar in the two groups. Compared to census data, the combination of RDD and community controls seems to be more representative of the general population than RDD controls alone. Furthermore, the inclusion of the community group had little impact on the magnitude of risk estimates for most variables, while enhancing statistical power.
  
  
  CONCLUSIONS
  Community-based recruitment was found to be an efficient and feasible method to recruit AA controls.
authors.affiliation: The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08901, USA. elisa.bandera@umdnj.edu
authors.forename: Elisa V
authors.initials: EV
authors.lastname: Bandera
authors.forename: Urmila
authors.initials: U
authors.lastname: Chandran
authors.forename: Gary
authors.initials: G
authors.lastname: Zirpoli
authors.forename: Susan E
authors.initials: SE
authors.lastname: McCann
authors.forename: Gregory
authors.initials: G
authors.lastname: Ciupak
authors.forename: Christine B
authors.initials: CB
authors.lastname: Ambrosone
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People; D001943:Breast Neoplasms / Q000453:epidemiology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000453:epidemiology*; D016022:Case-Control Studies; D035061:Control Groups; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008913:Minority Groups; D018579:Patient Selection; D012107:Research Design; D012307:Risk Factors; D044465:White People; D055815:Young Adult