Paper Information

We used data from 12701 respondents participating in a Belgian survey in 2022. Correlation coefficients between GHQ-12 and EQ-5D-5L were calculated at both the aggregate and item levels. Multidimensional scaling (MDS), exploratory factor analysis (EFA) and regression models were performed to investigate the underlying constructs that are associated with the items.

To the best of our knowledge, we present the first comparison of items and underlying constructs of GHQ-12 and EQ-5D-5L. The results showed that GHQ-12 can only partially predict the responses of EQ-5D-5L and the two instruments measure different constructs. Researchers should carefully consider conceptual legitimacy while applying the mapping technique and consider sensitivity analyses for the mapping estimates.

To explore the internal constructs of the concepts being measured by EQ-5D-5L (a health-related quality of life measure that can produce preference-based utility values) and the 12-item General Health Questionnaire (GHQ-12, a mental well-being measure), and to understand to what extent the items of EQ-5D-5L and GHQ-12 associate with each other.

Despite a moderate correlation (0.39) between the EQ-5D-5L and GHQ-12 total scores, only a trivial or weak correlation (<0.3) was observed between the first four EQ-5D-5L items and any GHQ-12 item. MDS and EFA showed the first four EQ-5D-5L dimensions were clustered together with EQ-VAS, positively-phrased GHQ-12 items were close to each other, while EQ-Anxiety/Depression and negatively-phrased GHQ-12 items were grouped with overall life satisfaction. In the regression models, not all GHQ-12 items had a significant coefficient to predict EQ-5D-5L responses.