title: "Back to the future": Influence of beliefs regarding the future on TTO answers.
abstract: BACKGROUND
  A common approach to obtain health state valuations is the time-tradeoff (TTO) method. Much remains unknown regarding the influence of responder characteristics on TTO answers. The objective of this study is to increase understanding of the influence that beliefs regarding future health and death, as well as desires to witness certain life events, have on respondents' health state valuations.
  
  
  METHODS
  An online survey was designed, including three TTO questions using a 10 year timeframe. Moreover, respondents completed demographic questions, the Health-Risk Attitude Scale (HRAS), the Expectations Regarding Aging (ERA) questionnaire, questions about beliefs regarding future health (i.e. life expectancy) and death (i.e. fear of death, belief in life after death and opinion about euthanasia), and about important life events taking place within the TTO timeframe. Regression analyses were performed in order to assess the influence of these different variables.
  
  
  RESULTS
  One thousand sixty-seven respondents were included in the analyses. The following variables were significantly associated with years traded off: ERA mental health (decrease), ERA physical health (increase), HRAS (increase), support for euthanasia (increase), fear of death (decrease) and consideration of an important life event (decrease). The explained variance of the final model was low (0.08).
  
  
  CONCLUSIONS
  TTO responses may be influenced by considerations of future health, including life events and attitudes regarding health risks and death. Further investigation of TTO responses remains warranted.
authors.affiliation: Institute of Health Policy & Management, Erasmus University Rotterdam, Rotterdam, The Netherlands. floortjevannooten@hotmail.com.
authors.forename: F E
authors.initials: FE
authors.lastname: van Nooten
authors.affiliation: Institute of Health Policy & Management, Erasmus University Rotterdam, Rotterdam, The Netherlands. vanexel@bmg.eur.nl.
authors.forename: N J A
authors.initials: NJ
authors.lastname: van Exel
authors.affiliation: Quantify Research, Stockholm, Sweden. daniel.eriksson@quantifyresearch.com.
authors.forename: D
authors.initials: D
authors.lastname: Eriksson
authors.affiliation: Institute of Health Policy & Management, Erasmus University Rotterdam, Rotterdam, The Netherlands. brouwer@bmg.eur.nl.|Institute for Medical Technology Assessment, Erasmus University Rotterdam, Rotterdam, The Netherlands. brouwer@bmg.eur.nl.
authors.forename: W B F
authors.initials: WB
authors.lastname: Brouwer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology*; D001293:Attitude to Death; D001294:Attitude to Health; D005260:Female; D006304:Health Status; D006801:Humans; D008017:Life Expectancy / Q000639:trends*; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D011788:Quality of Life / Q000523:psychology*; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D055815:Young Adult