Internal structure, reliability and cross-cultural validity of the Warwick-Edinburgh Mental Wellbeing Scale in three European populations.

Background: The Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS), a questionnaire designed for the assessment of mental well-being, is widely used in different countries and cultures worldwide. However, there is a lack of studies examining its metric performance and measurement invariance across countries.

Objective: This study aims to examine the internal structure, reliability and cross-country validity of the WEMWBS in three European populations.

Methods: WEMWBS data collected in 2016 from three representative population health surveys from an autonomous region in Spain (Catalonia) and two countries (Denmark and the UK) were used (n=13 940). The mean WEMWBS Scores were compared between populations. The internal consistency (ω coefficients), internal structure (confirmatory factor analyses (CFA) and bifactor exploratory structural equation models), reliability (item response theory models, item and test information functions), and cross-cultural comparability (multigroup CFA) of the WEMWBS were assessed.

Findings: Differences in mean scores observed between regions merit further study. The WEMWBS showed high internal consistency across countries (ω=0.942). The unidimensionality of the scale was confirmed overall and for each population. Evidence of reliability and of measurement invariance at the configural, scalar and metric levels was found.

Conclusions And Implications: The results support the use of the WEMWBS in different cultures to inform the understanding of population well-being in public health and its possible use as an outcome measure in clinical studies.