title: Recruitment and retention of urban schoolchildren into a randomized double-blind vitamin D supplementation trial.
abstract: BACKGROUND
  While rarely used for supplementation trials in the United States, schools present a practical alternative to a clinical setting.
  
  
  OBJECTIVE
  We describe the successful recruitment and retention of urban schoolchildren into a 6-month randomized, double-blind vitamin D3 supplementation trial.
  
  
  METHODS
  Boston-area urban schoolchildren, aged 8-15 years, were recruited in 2011-2012 through classroom and auditorium presentations. Informed consent forms in five languages were sent home to parents. Retention methods included regular telephone calls and gift cards for completed study visits.
  
  
  RESULTS
  In total, 691 schoolchildren enrolled. Their mean (standard deviation) age was 11.7 (1.4) years; 59% were racial/ethnic minorities and 68% qualified for free or reduced-price school meals. Multi-level, culturally sensitive, creative approaches contributed to success in recruitment and retention. Of 691 participants, 81% completed the 6-month intervention period. Reasons for attrition included missed appointments and fear of a blood draw. More children from households with higher incomes were retained than those from households with lower incomes (85% vs 79%, respectively, P = 0.04).
  
  
  CONCLUSIONS
  The need for three fasting blood draws over the 6-month supplementation period was a limiting factor in the recruitment and retention of children in this study.
  
  
  CONCLUSIONS
  Recruitment of urban children into a school-based randomized controlled trial represents a feasible approach for a supplementation study. Particular attention to children of lower socioeconomic status may enhance participation and retention when conducting intervention studies among diverse populations.
authors.affiliation: Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA jennifer.sacheck@tufts.edu.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Sacheck
authors.affiliation: Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
authors.forename: Maria I
authors.initials: MI
authors.lastname: Van Rompay
authors.affiliation: Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Olson
authors.affiliation: Department of Public Health and Community Medicine, Tufts University, Boston, MA, USA.
authors.forename: Virginia R
authors.initials: VR
authors.lastname: Chomitz
authors.affiliation: MassGeneral Hospital for Children and Harvard Medical School, Boston, MA, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Goodman
authors.affiliation: Divisions of Adolescent Medicine and Endocrinology, Hasbro Children's Hospital, Providence, RI, USA.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Gordon
authors.affiliation: Department of Public Health and Community Medicine, Tufts University, Boston, MA, USA.
authors.forename: Misha
authors.initials: M
authors.lastname: Eliasziw
authors.affiliation: Boston University School of Medicine, Boston, MA, USA.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Holick
authors.affiliation: Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
authors.forename: Christina D
authors.initials: CD
authors.lastname: Economos
mesh_terms: D000293:Adolescent; D001900:Boston; D002648:Child; D019587:Dietary Supplements / Q000706:statistics & numerical data*; D004311:Double-Blind Method; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D018579:Patient Selection; D012574:Schools / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D014505:Urban Population / Q000706:statistics & numerical data*; D014807:Vitamin D / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000188:drug therapy* / Q000517:prevention & control*
chemical_list: D014807:Vitamin D
keywords: Recruitment; children; randomized controlled trial; retention; school-based intervention; vitamin D