Skip to content Skip to navigation
University of Warwick
  • Study
  • |
  • Research
  • |
  • Business
  • |
  • Alumni
  • |
  • News
  • |
  • About

University of Warwick
Publications service & WRAP

Highlight your research

  • WRAP
    • Home
    • Search WRAP
    • Browse by Warwick Author
    • Browse WRAP by Year
    • Browse WRAP by Subject
    • Browse WRAP by Department
    • Browse WRAP by Funder
    • Browse Theses by Department
  • Publications Service
    • Home
    • Search Publications Service
    • Browse by Warwick Author
    • Browse Publications service by Year
    • Browse Publications service by Subject
    • Browse Publications service by Department
    • Browse Publications service by Funder
  • Help & Advice
University of Warwick

The Library

  • Login
  • Admin

Which health-related quality-of-life outcome when planning randomized trials : disease-specific or generic, or both? A common factor model

Tools
- Tools
+ Tools

Ades, A. E., Lu, G. and Madan, Jason (2013) Which health-related quality-of-life outcome when planning randomized trials : disease-specific or generic, or both? A common factor model. Value in Health, 16 (1). 185- 194. doi:10.1016/j.jval.2012.09.012

An open access version can be found in:
  • https://www.valueinhealthjournal.com/art...
Official URL: https://doi.org/10.1016/j.jval.2012.09.012

Request Changes to record.

Abstract

The primary outcomes in trials are usually disease-specific measures (DSMs) designed to be responsive to changes in the condition caused by treatment. For purposes of cost-effectiveness analysis, treatment effects on the DSM are often mapped into treatment effects on a generic health-related quality-of-life (QOL) scale, such as EuroQol five-dimensional questionnaire. Trialists have the option of including generic QOL measures as trial outcomes. We consider the relative efficiency (estimate divided by its standard error) of treatment effects derived from the DSM, the generic QOL, the generic QOL indirectly estimated from the mapped DSM, and a pooled estimate combining the direct and indirect information on the generic QOL. By using a common factor theory of the relationship between the DSM and the generic QOL, we define the circumstances under which indirectly estimated generic QOL is more efficient than the direct one and when a pooled QOL estimate is more efficient than the DSM estimate. As long as the DSM is more responsive, there is always a threshold sample size above which the indirect estimate has better precision than the direct estimate. This threshold, however, increases as the (1) relative responsiveness ratio of the DSM to the generic QOL increases, (2) precision of the estimated mapping coefficient increases, and (3) true effect becomes smaller. The pooled estimate on the generic QOL may be more efficient than the DSM itself unless the reliability of the DSM is particularly high. Trials powered on DSMs are likely to have sufficient power to detect treatment effect on the generic QOL if a pooled estimate is used. We conclude that generic QOL instruments should be routinely included in randomized controlled trials. Information on mapping coefficients and on relative responsiveness should be collected more systematically to facilitate both evidence synthesis and trial design. © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc.

Item Type: Journal Article
Subjects: R Medicine > R Medicine (General)
Divisions: Faculty of Science, Engineering and Medicine > Medicine > Warwick Medical School > Clinical Trials Unit
Journal or Publication Title: Value in Health
Publisher: Elsevier Inc.
ISSN: 1098-3015
Official Date: 2013
Dates:
DateEvent
2013Published
1 January 2013Accepted
Volume: 16
Number: 1
Page Range: 185- 194
DOI: 10.1016/j.jval.2012.09.012
Status: Peer Reviewed
Publication Status: Published
Access rights to Published version: Open Access
Funder: Diagnostic Services Manitoba, Medical Research Council (Great Britain) (MRC)
Grant number: G0901488
Open Access Version:
  • https://www.valueinhealthjournal.com/art...

Request changes or add full text files to a record

Repository staff actions (login required)

View Item View Item
twitter

Email us: wrap@warwick.ac.uk
Contact Details
About Us