COMPARING THE DESCRIPTIVE PERFORMANCE OF EQ-5D 3L AND 5L IN THE GENERAL POPULATION IN FRANCE

Abstract

Background: The purpose of this study was to assess the descriptive performance of the two EQ-5D questionnaires, with three and five levels, using data from the EQ-5D-5L health status valuation study.
Method: EQ-5D-5L, EQ-5D-3L and EQ-VAS were collected during the valuation study from 1,143 French residents age 18 and over, with a stratified random sampling frame to ensure that the distribution of age, gender and socio-economic status matched that reported by national statistics. A comparative analysis of results was performed including measuring consistency between 3L and 5L health states, redistribution effects for each 3L dimension, discriminatory power using the Shannon Index and the Shannon Evenness Index. VAS scoring collected at the two different times of interviews were compared. Differences were related to inconsistent 5L-3L health states.
Results: Global consistency was 92.3%. Overall Level 1 frequency went down 6.8%. The highest shifts to more severe levels were for Pain & Discomfort and Anxiety & Depression. The Shannon Index improved 55% and the Shannon Evenness Index 6%. No or little discrepancy was observed between the initial and final VAS for 76.9% (879/1143) of pairs. Inconsistent answers had a greater probability of leading to differences in VAS values.
Conclusion: The study confirmed results from other similar publications: the 5 level questionnaire offers a better descriptive system than the 3 level questionnaire. Answers to both questionnaires were highly consistent. Limitations to our study are the low rate of severe health states observed in the general population.