title: Consistency between stated and revealed preferences: a discrete choice experiment and a behavioural experiment on vaccination behaviour compared.
abstract: BACKGROUND
  Discrete Choice Experiments (DCEs) are increasingly used in studies in healthcare research but there is still little empirical evidence for the predictive value of these hypothetical situations in similar real life circumstances. The aim of this paper is to compare the stated preferences in a DCE and the accompanying questionnaire with the revealed preferences of young parents who have to decide whether to vaccinate their new born child against hepatitis B.
  
  
  METHODS
  A DCE asking parents to decide in which scenario they would be more inclined to vaccinate their child against hepatitis B. The stated preference was estimated by comparing the per respondent utility of the most realistic scenario in which parents could choose to vaccinate their child against hepatitis B, with the utility of the opt-out, based on the mixed logit model from the DCE. This stated preference was compared with the actual behaviour of the parents concerning the vaccination of their new born child.
  
  
  RESULTS
  In 80% of the respondents the stated and revealed preferences corresponded. The positive predictive value is 85% but the negative predictive value is 26%.
  
  
  CONCLUSIONS
  The predictive value of the DCE in this study is satisfactory for predicting the positive choice but not for predicting the negative choice. However, the behaviour in this study is exceptional in the sense that most people chose to vaccinate. Future studies should focus on behaviours with a larger variance in the population.
authors.affiliation: National Institute of Health and the Environment, Centre for Prevention and Health Services Research, P.O. Box 1 3720, Bilthoven, BA, The Netherlands. mattijs.lambooij@rivm.nl.
authors.forename: Mattijs S
authors.initials: MS
authors.lastname: Lambooij
authors.affiliation: National Institute of Health and the Environment, Centre for Infectious Disease Control, P.O. Box 1 3720, Bilthoven, BA, The Netherlands. irene.harmsen@rivm.nl.|Maastricht University, Work & Social Psychology, P.O. Box 616, Maastricht, MD, 6200, The Netherlands. irene.harmsen@rivm.nl.
authors.forename: Irene A
authors.initials: IA
authors.lastname: Harmsen
authors.affiliation: National Institute of Health and the Environment, Centre for Prevention and Health Services Research, P.O. Box 1 3720, Bilthoven, BA, The Netherlands. jorien.veldwijk@rivm.nl.|Julius Centre for Health Sciences and Primary Care University Medical Center Utrecht, P.O. Box 85500, Utrecht, GA, 3508, The Netherlands. jorien.veldwijk@rivm.nl.
authors.forename: Jorien
authors.initials: J
authors.lastname: Veldwijk
authors.affiliation: National Institute of Health and the Environment, Centre for Infectious Disease Control, P.O. Box 1 3720, Bilthoven, BA, The Netherlands. hester.de.melker@rivm.nl.
authors.forename: Hester
authors.initials: H
authors.lastname: de Melker
authors.affiliation: National Institute of Health and the Environment, Centre for Infectious Disease Control, P.O. Box 1 3720, Bilthoven, BA, The Netherlands. liesbeth.mollema@rivm.nl.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Mollema
authors.affiliation: National Institute of Health and the Environment, Centre for Infectious Disease Control, P.O. Box 1 3720, Bilthoven, BA, The Netherlands. yolanda.van.weert@rivm.nl.
authors.forename: Yolanda W M
authors.initials: YW
authors.lastname: van Weert
authors.affiliation: National Institute of Health and the Environment, Centre for Prevention and Health Services Research, P.O. Box 1 3720, Bilthoven, BA, The Netherlands. ardine.de.wit@rivm.nl.|Julius Centre for Health Sciences and Primary Care University Medical Center Utrecht, P.O. Box 85500, Utrecht, GA, 3508, The Netherlands. ardine.de.wit@rivm.nl.
authors.forename: G Ardine
authors.initials: GA
authors.lastname: de Wit
mesh_terms: D000293:Adolescent; D000328:Adult; D002755:Choice Behavior; D005260:Female; D006306:Health Surveys / Q000379:methods / Q000706:statistics & numerical data; D006509:Hepatitis B / Q000517:prevention & control*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010290:Parents / Q000523:psychology; D011795:Surveys and Questionnaires; D014611:Vaccination / Q000523:psychology*; D055815:Young Adult
chemical_list: D017325:Hepatitis B Vaccines