title: Characteristics of responders to a request for a buccal cell specimen among survivors of childhood cancer and their siblings.
abstract: OBJECTIVE
  Analysis of biological samples in large cohort studies may provide insight into the mechanism of, and risk factors for, disease onset and progression.
  
  
  METHODS
  This study describes the methods used to collect biological samples from a large multi-center cohort of childhood cancer survivors and siblings of childhood cancer survivors and evaluates the predictors of a positive response among these individuals.
  
  
  RESULTS
  Among survivors, female sex, white race/ethnicity, college graduation, never smoking, accessing the healthcare system in the past 2 years, and having a second malignant neoplasm were the strongest predictors of returning a sample. Among siblings, a similar demographic profile defined those likely to submit the requested sample.
  
  
  CONCLUSIONS
  To reduce selection bias and increase the value of these samples for future analysis, additional phone calls and reminders targeting non-responders are needed to improve response rates among those least likely to respond to a single mailed request.
authors.affiliation: Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA. kiri.ness@stjude.org
authors.forename: Kirsten K
authors.initials: KK
authors.lastname: Ness
authors.forename: Chenghong
authors.initials: C
authors.lastname: Li
authors.forename: Pauline A
authors.initials: PA
authors.lastname: Mitby
authors.forename: Gretchen A
authors.initials: GA
authors.lastname: Radloff
authors.forename: Ann C
authors.initials: AC
authors.lastname: Mertens
authors.forename: Stella M
authors.initials: SM
authors.lastname: Davies
authors.forename: Sue
authors.initials: S
authors.lastname: Hammond
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Armstrong
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Robison
mesh_terms: D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009061:Mouth Mucosa / Q000473:pathology*; D015337:Multicenter Studies as Topic; D009369:Neoplasms / Q000175:diagnosis*; D011237:Predictive Value of Tests; D035781:Siblings; D013048:Specimen Handling; D017741:Survivors