title: Extrinsic goals and time tradeoff.
abstract: BACKGROUND
  The aim of this article is to investigate the extrinsic goals hypothesis in time tradeoff (TTO). The extrinsic goal of interest here is seeing children through to maturity. In TTO, the time it takes to attain this goal becomes a target life expectancy, with no trades happening below the critical value implied by the target, no matter how severe the health state.
  
  
  METHODS
  A combined quantitative and qualitative approach was used to elicit values for 4 EQ-5D states from 30 recent mothers. The qualitative analysis allowed the researchers to explore with participants whether a target life expectancy was being used.
  
  
  RESULTS
  The differences in the visual analogue scale and TTO scores of the mothers compared with the general population suggest that the mothers value life-years differently than the general population does. The finding was also consistent with the target life expectancy hypothesis. However, the interview data were not so strongly supportive of the target life expectancy hypothesis. Although some women suggested this had motivated their responses to the TTO, the interviews paint a more complicated and nuanced picture of what drives a person's responses to health valuation surveys.
  
  
  CONCLUSIONS
  A higher value was assigned to life-years relative to quality of life by recent parents, but there was no reduction in the willingness to trade per se. Parenthood affects how much one will trade for better health but not whether one will trade in the 1st place. This conclusion became apparent only when the qualitative and quantitative data were combined.
authors.affiliation: Health Economics Research Unit, University of Aberdeen, Scotland. m.vanderpol@abdn.ac.uk
authors.forename: Marjon
authors.initials: M
authors.lastname: van der Pol
authors.forename: Alan
authors.initials: A
authors.lastname: Shiell
mesh_terms: D000328:Adult; D015982:Bias; D002648:Child; D002675:Child, Preschool; D002755:Choice Behavior; D005260:Female; D006304:Health Status; D006801:Humans; D007223:Infant; D008017:Life Expectancy; D009035:Mothers / Q000523:psychology*; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013997:Time Factors