Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2008 Jul-Aug;15(4):218-23.
doi: 10.1080/09286580801979417.

Vision and quality of life: development of methods for the VisQoL vision-related utility instrument

Affiliations

Vision and quality of life: development of methods for the VisQoL vision-related utility instrument

Stuart Peacock et al. Ophthalmic Epidemiol. 2008 Jul-Aug.

Abstract

Purpose: To describe the methods and innovations used in constructing the VisQoL, a vision-related utility instrument for the health economic evaluation of eye care and rehabilitation programs.

Methods: The VisQoL disaggregates vision into six items. Utilities were estimated for item worst responses (the worst level for each item, with all other items at their best level) and VisQoL all-worst responses (all items at their worst level) using the time trade-off procedure. Time trade-off questions require people to imagine living a fixed number of years with a particular health condition and then indicate how many of those years of life they would be willing to trade to have perfect health. Where respondents indicated a health state was "worse than death" negative utilities were estimated. Time trade-off questions minimized the "focusing effect," which occurs if respondents discount the fact that all other aspects of health are at their best when answering questions, by using pictorial and verbal aids.

Results: Item utilities were combined using a multiplicative model, and VisQoL model utilities placed on a scale where 0.00 and 1.00 represent full health and death, respectively. The VisQoL allows utilities to be calculated for a wide range of vision-related conditions.

Conclusion: The 6-item VisQoL has excellent psychometric properties and is specifically designed to be sensitive to vision-related quality of life. It is the first instrument to permit the rapid estimation of utility values for use in economic evaluations of vision-related programs.

PubMed Disclaimer

Figures

Figure 1
Figure 1
An example of a visual aid for time trade off questions.
Figure 2
Figure 2
Mapping “model” onto “life-death” utilities. VisQol = DU(LD)-rescaled disutility measured on a best health to death scale; Vision and Quality of Life Index; DU = disutility.

References

    1. Clear Insight: The Economic Impact and Cost of Vision Loss in Australia. Melbourne: Access Economics; 2004. Eye Research Australia, Access Economics.
    1. Taylor HR, McCarty CA, Nanjan MB. Vision impairment predicts five-year mortality. Trans Am Ophthalmol Soc. 2000;98:91–6. - PMC - PubMed
    1. Weih LM, Hassell JB, Keeffe JE. Assessment of the impact of vision impairment. Invest Ophthalmol Vis Sci. 2002;43:927–35. - PubMed
    1. Wang JJ, Mitchell P, Smith W, et al. Incidence of nursing home placement in a defined community. Med J Aust. 2001;174:271–5. - PubMed
    1. Wang JJ, Mitchell P, Smith W, et al. Factors associated with use of community support services in an older Australian population. Aust & NZ J Pub Health. 1999;23:147–53. - PubMed