title: Primary care research: difficulties recruiting preschool children to clinical trials.
abstract: OBJECTIVE
  The aims of the present study were to report difficulties experienced recruiting preschool children to a clinical trial and to report the acceptability of a dental intervention to their parents.
  
  
  METHODS
  The study was a randomized controlled trial (RCT).
  
  
  METHODS
  The study took place in community dental clinics, health centres and patient homes.
  
  
  METHODS
  Health visitors were used to recruit 508 children aged between 18 and 30 months from high caries areas of South Wales. Children with caries-free first primary molars were entered into a placebo-controlled individual RCT of fissure sealants. All children received a standard package of dental health education. Children in the test group had their first primary molars sealed with glass ionomer. All children were reviewed once. Families were asked to rate the acceptability of procedures.
  
  
  RESULTS
  Health visitors referred 1228 children for screening, but only 547 were seen (44.5%) and 508 subjects were recruited to the trial. Of these, 449 (88.4%) were seen at follow-up. Some 667 children missed 1610 visits at baseline, and 373 of those recruited missed an appointment. At follow-up, 1056 appointments were staffed to review 449 children. Three-quarters of parents reported the examination to be very easy.
  
  
  CONCLUSIONS
  Preschool children are difficult to access for community trials. Dental examinations and sealant placement were acceptable to the majority of families who were seen.
authors.affiliation: Department of Dental Health and Biological Sciences, Dental School, Cardiff University, Cardiff, UK. Chadwickbl@cardiff.ac.uk
authors.forename: B L
authors.initials: BL
authors.lastname: Chadwick
authors.forename: E T
authors.initials: ET
authors.lastname: Treasure
mesh_terms: D002675:Child, Preschool; D018865:Dental Research / Q000379:methods*; D006801:Humans; D007223:Infant; D010290:Parents / Q000523:psychology; D010342:Patient Acceptance of Health Care; D010352:Patient Dropouts; D018579:Patient Selection; D010895:Pit and Fissure Sealants; D011320:Primary Health Care; D016032:Randomized Controlled Trials as Topic; D014852:Wales
chemical_list: D010895:Pit and Fissure Sealants