Valuing health status using VAS and TTO: What lies behind the numbers?
AbstractIt is well known that different methods of eliciting the valuations attached to various health states, such as the Visual Analogue Scale (VAS) and the Time Trade Off (TTO), yield different results. This study gathers qualitative data from a group of 43 respondents who had previously taken part in a large scale national study which set out to elicit the values attached by individuals to various health states using both the VAS and the TTO techniques. The findings of this study raised three questions which are of particular interest here: (1) Why are some states that are rated better than dead on the VAS often rated as worse than dead in TTO? (2) Why are some respondents unwilling to trade off any time at all in order to avoid a health state that they place below full health on the VAS? (3) Why are TTO valuations of older respondents for the more severe health states lower than those of the younger age groups? This study has uncovered qualitative evidence on each of these three key issues. Regarding the first question, many respondents did not appear to interpret a better than dead VAS score as a strict preference for spending 10 years in a health state over immediate death. Several different factors appeared to contribute towards this, an important one being the tendency of respondents to ignore the duration of the health state during the VAS task. Regarding the second question, there is evidence of the existence of a "threshold of tolerability" below which states would have to fall before some respondents would be willing to give up any time at all on the TTO. Regarding the last question, it appears that older respondents are less likely to find the worse than dead TTO scenario plausible than those in the younger age groups. However, whilst this may explain why older respondents attach lower worse than dead valuations to health states, it does not appear to account for the entire difference in TTO valuations between the two age groups. In addition, it appears that older respondents may be less prepared to live for the next 10 years in a diminished health state.
Download InfoIf you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
Bibliographic InfoArticle provided by Elsevier in its journal Social Science & Medicine.
Volume (Year): 45 (1997)
Issue (Month): 8 (October)
Contact details of provider:
Web page: http://www.elsevier.com/wps/find/journaldescription.cws_home/315/description#description
You can help add them by filling out this form.
CitEc Project, subscribe to its RSS feed for this item.
- Burstrom, Kristina & Johannesson, Magnus & Diderichsen, Finn, 2006. "A comparison of individual and social time trade-off values for health states in the general population," Health Policy, Elsevier, vol. 76(3), pages 359-370, May.
- Mandy Ryan & Mabelle Amaya-Amaya, 2005. "' Threats ' to and hopes for estimating benefits," Health Economics, John Wiley & Sons, Ltd., vol. 14(6), pages 609-619.
- Dolan, Paul & Stalmeier, Peep, 2003. "The validity of time trade-off values in calculating QALYs: constant proportional time trade-off versus the proportional heuristic," Journal of Health Economics, Elsevier, vol. 22(3), pages 445-458, May.
- Devlin, N. & Tsuchiya, A. & Buckingham, K. & Tilling, C., 2009.
"A uniform Time Trade Off method for states better and worse than dead: feasibility study of the ‘lead time’ approach,"
09/08, Department of Economics, City University London.
- Nancy J. Devlin & Aki Tsuchiya & Ken Buckingham & Carl Tilling, 2011. "A uniform time trade off method for states better and worse than dead: feasibility study of the ‘lead time’ approach," Health Economics, John Wiley & Sons, Ltd., vol. 20(3), pages 348-361, March.
- Joshua A. Salomon & Christopher J.L. Murray, 2004. "A multi-method approach to measuring health-state valuations," Health Economics, John Wiley & Sons, Ltd., vol. 13(3), pages 281-290.
- Angela Robinson & Anne Spencer, 2006. "Exploring challenges to TTO utilities: valuing states worse than dead," Health Economics, John Wiley & Sons, Ltd., vol. 15(4), pages 393-402.
- Anne Spencer, 2000. "Testing the Additive Independence Assumption in the QALY Model," Working Papers 427, Queen Mary, University of London, School of Economics and Finance.
- Rachel Baker & Angela Robinson, 2004. "Responses to standard gambles: are preferences 'well constructed'?," Health Economics, John Wiley & Sons, Ltd., vol. 13(1), pages 37-48.
- Trude Arnesen & Mari Trommald, 2005. "Are QALYs based on time trade-off comparable? - A systematic review of TTO methodologies," Health Economics, John Wiley & Sons, Ltd., vol. 14(1), pages 39-53.
- Attema, Arthur & Brouwer, Werner, 2012. "Deriving time discounting correction factors for TTO tariffs," MPRA Paper 37002, University Library of Munich, Germany.
- Attema, Arthur E. & Brouwer, Werner B.F., 2012. "A test of independence of discounting from quality of life," Journal of Health Economics, Elsevier, vol. 31(1), pages 22-34.
- Joanna Coast, 1999. "The appropriate uses of qualitative methods in health economics," Health Economics, John Wiley & Sons, Ltd., vol. 8(4), pages 345-353.
- Brazier, J, 2005. "Current state of the art in preference-based measures of health and avenues for further research," MPRA Paper 29762, University Library of Munich, Germany.
- Benjamin M. Craig & Sulabha Ramachandran, 2006. "Relative risk of a shuffled deck: a generalizable logical consistency criterion for sample selection in health state valuation studies," Health Economics, John Wiley & Sons, Ltd., vol. 15(8), pages 835-848.
- F. E. van Nooten & X. Koolman & W. B. F. Brouwer, 2009. "The influence of subjective life expectancy on health state valuations using a 10 year TTO," Health Economics, John Wiley & Sons, Ltd., vol. 18(5), pages 549-558.
- Peep F. M. Stalmeier & Jan J. V. Busschbach & Leida M. Lamers & Paul F. M. Krabbe, 2005. "The gap effect: discontinuities of preferences around dead," Health Economics, John Wiley & Sons, Ltd., vol. 14(7), pages 679-685.
- Oliver, Adam, 2013. "Testing the rate of preference reversal in personal and social decision-making," Journal of Health Economics, Elsevier, vol. 32(6), pages 1250-1257.
- Benjamin M. Craig, 2009. "The duration effect: a link between TTO and VAS values," Health Economics, John Wiley & Sons, Ltd., vol. 18(2), pages 217-225.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Zhang, Lei).
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.
Please note that corrections may take a couple of weeks to filter through the various RePEc services.