Valuing health status using VAS and TTO: What lies behind the numbers?
It 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.
If 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.
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|
|Order Information:|| Postal: http://www.elsevier.com/wps/find/supportfaq.cws_home/regional|
When requesting a correction, please mention this item's handle: RePEc:eee:socmed:v:45:y:1997:i:8:p:1289-1297. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Shamier, Wendy)
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.