Measuring inequality in quality of life: further evidence that the EQ-5D-5L may underestimate it

Journal article

Purpose: A previous study found that individuals with identical EQ-5D-5L profiles reported systematically higher EQ VAS scores with increasing educational attainment, which suggests a ‘hidden’ socioeconomic gradient not captured by the EQ-5D-5L. This study examines the robustness and generalisability of these findings using multi-country data. Methods: We analysed data from 32,327 respondents aged 25 to 79 years across eight high-income countries: Australia, Canada, France, Germany, the Netherlands, New Zealand, the UK, and the US. The data came from the EQ-DAPHNIE study. Within ten selected EQ-5D-5L health profiles, we used linear regression models to estimate the associations between EQ VAS scores and educational attainment or subjective income status, adjusting for age, sex, and country. Results: We observed a consistent educational gradient in EQ VAS scores across most EQ-5D-5L profiles. Tertiary education was associated with higher scores in all ten profiles, with effects statistically significant at p < 0.10 in seven, of which four at p < 0.01. Income status showed an even stronger gradient, with significant associations in nine of the ten profiles. These patterns were evident in all eight countries. Conclusion: These multi-country findings provide robust evidence of a socioeconomic gradient in EQ VAS scores among respondents who report identical EQ-5D-5L health profiles, over and above what is reflected in the five EQ-5D-5L dimensions. This pattern has implications for the use of EQ-5D-5L values in equity-informative health technology assessment and population health monitoring.

Authors: Lamu, AN; Chen, G; Cheng, LJ; Olsen, JA

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer
• Journal: Quality of Life Research
• Volume: 35
• Issue: 8
• Article number: 199
• Publication date: 2026-06-15
• Acceptance date: 2026-05-11
• DOI: 10.1007/s11136-026-04294-w
• EISSN: 1573-2649
• ISSN: 0962-9343
• Language: English
• Keywords: Health-related quality of life; Socioeconomic gradient; EQ-DAPHNIE; EQ VAS; Health inequality; EQ-5D-5L