The development of a new international generic measure (EQ-HWB): face validity and psychometric stages in Argentina

Objectives This study aimed to present the face validity and psychometric stages performed in Spanish in Argentina, the only Spanish-speaking country of an international collaboration that undertook the construction of a new measure that can be used in economic evaluation across health, social care, and public health, the EQ EQ-HWB (EQ Health and Wellbeing). We also explored the relationship among 3-level version EQ-5D (EQ-5D-3L), 5-level version EQ-5D (EQ-5D-5L), and EQ-HWB. Methods Face validity was based on semistructured face to face interviews of a purposive sample to explore translatability of language and concepts of 97 candidate items, translated into Argentina Spanish. The psychometric evaluation using an online panel assessed the psychometric properties of 64 items that were carried forward (floor and ceiling effects, item correlations, known-group differences in relevant prespecified subgroups by the international and local teams, exploratory and confirmatory factor analysis, and item response theory). EQ-5D-3L, EQ-5D-5L, and EQ-HWB correlations were explored. Results In the face validity stage, 24 interviews with carers, general public, patients, and users of social services were included. Most items showed adequate face validity. In the psychometric assessment, 497 participants were recruited (64% reporting a long-term health condition). Most of the items showed adequate psychometrics in an Argentinian context. EQ-5D-3L and EQ-5D-5L had strong correlations, and EQ-HWB was moderately correlated to EQ visual analog scale. The Argentina team recommended 23 of the final 25 items. Conclusions The assessment of Spanish items contributed to the overall development of EQ-HWB and helped inform the design of an internationally relevant 25-item and a short 9-item measure intended to be used in economic evaluations