Does the EQ-5D reflect lost earnings?

Area of Science:

• Health economics
• Decision analysis
• Psychometrics

Background:

• Productivity costs are a key methodological issue in healthcare economic evaluations.
• Traditionally included in the numerator, there's concern they may be double-counted if already in the denominator (QALYs).
• This arises if individuals consider income effects when valuing health states.

Purpose of the Study:

• To determine if respondents spontaneously consider income effects when valuing EQ-5D health states using the time trade-off (TTO) method.
• To assess if considering income influences valuations.
• To examine the impact of explicit instructions on valuations.

Main Methods:

• An online survey of 321 Dutch general population members.
• Three time trade-off (TTO) exercises to value four EQ-5D health states.
• Investigated spontaneous inclusion of income effects, followed by instructed inclusion/exclusion and explicit income loss information.

Main Results:

• 49% of respondents spontaneously included income effects.
• Few significant valuation differences were found between those who did and did not spontaneously include income.
• Explicit instructions showed aggregate but inconsistent individual-level effects; explicit income loss information lowered valuations.

Conclusions:

• Income losses do not significantly affect health state valuations in this study.
• Evidence suggests potential double-counting of productivity costs may be less of a concern than previously thought.
• Further research may be needed to fully understand the nuances of income considerations in health valuation.