Presentation (CTI)

OBJECTIVES: Around 20 European countries do not have their own national scoring system for the EQ-5D-5L, a widely used measure of health quality. Researchers and health authorities still need these scores when deciding whether a new treatment is worth its cost. When no local system exists, researchers borrow one from another country, often without justification. This guesswork can quietly skew health economic analyses. This study aimed to find which European scoring system is the safest to borrow and to build an R Shiny tool so researchers can check this for their own data.
METHODS: Using stratified sampling, 1,000 health state profiles were generated across five equally represented severity bands ranging from mild to severe. Each profile was scored using all available European scoring systems. An average score across all systems per profile was calculated as our European reference point. Two measures assessed how closely each system tracked this reference: mean absolute difference (MAD), capturing the average scoring gap, and Pearson correlation, capturing whether scores move in the same direction. Both were examined across five severity groups and are available through an R Shiny tool.
RESULTS: Norway ranked first with the lowest MAD of 0.041 and a near-perfect correlation of 0.992, performing consistently across all severity levels. Belgium and Portugal followed with MADs of 0.045 and 0.046 respectively, showing the same cross-severity stability. Lower-ranked systems deteriorated in specific severity groups despite acceptable overall averages.
CONCLUSIONS: Norway is the recommended first choice when borrowing a scoring system, with Belgium and Portugal as backup options to be tested in sensitivity analyses. The choice should never rest on a single overall number since performance across severity levels matters equally. The R Shiny tool makes this assessment straightforward for any researcher and study population.