Does EQ-5D measure the most relevant aspects of health across cultures? Findings from a multi-country qualitative and card-sorting study

The EQ-5D is a widely used measure of health-related quality of life (HRQoL) in health services and economic evaluations globally. However, its cross-cultural content validity remains underexplored. This study assesses the relevance and adequacy of EQ-5D across diverse cultural contexts, spanning seven countries from three regions (Europe, Asia and the Americas). The objectives were to evaluate EQ-5D’s coverage of important dimensions of poor health, and to explore cross-country similarities and differences. Semi-structured interviews (N=159) incorporating card-sorting techniques were conducted, with 94 interviews subsampled to improve focus and quality of analyses: Argentina (n=14), Canada (n=14), China (n=15), India (n=12), Indonesia (n=12), the Netherlands (n=13), and Spain (n=14). Thematic analyses were complemented by descriptive quantitative analyses of flashcard listings (n=505). Across all countries, interviewees spontaneously nominated the five EQ-5D dimensions as the most important aspects of poor health. In the card-sorting exercise, seven dimensions were selected and ranked by at least one participant in each country: five of these were covered by EQ-5D. Aspects of poor health viewed as important across countries, but not captured by EQ-5D, were mainly social. Several additional country- or region-specific dimensions of poor health were also identified but were less frequently nominated. This study found that EQ-5D covers core aspects of poor health which are considered relevant across diverse geographical and cultural settings, supporting the current use of the instrument internationally. Further local validation using the methods applied in this study and psychometric testing of the instrument are recommended.