Objectives: A new broad generic measure of quality-of-life for use in economic evaluations of interventions across health-care, social-care, and public health was developed by an international consortium-The E-QALY Project. This instrument shares a core items with existing multi-attribute utility instruments as the EQ-5D, while comparatively expanding on the coverage of health and social-care related dimensions. In order to better understand the content offered by each instrument, the aim of this study was to examine the extent to which the E-QALY project measure and EQ-5D overlap..

Methods: A sample of 903 USA-based respondents completed a survey administered via online panel. Beyond the E-QALY item pool, the survey also included the EQ-5D-5L and 3L, alongside with questions about sociodemographic characteristics and long-standing health conditions. Analysis included item-item (Spearman’s) correlations and the comparison of patterns of response (distributions and ceiling effects) between the measures.

Results: Strong associations were found between the physical function and pain dimensions of the EQ-5D and E-QALY project measure (r>0.5). The EQ-5D dimension Anxiety/Depression appears to be strong correlated with the E-QALY project measure dimensions Depression, Anxiety, Relationships, Coping and Fatigue (r>0.6). Among the individuals that reported full health on the EQ-5D (n=161), items on the E-QALY project measure identified some ceiling effects, particularly “feeling exhausted”, whereas problems were reported by n=74 (46% of those in full health). When looking at specific health conditions, the desegregated presentation of the dimensions Anxiety and Depression seems to increase the sensitivity and decrease the specificity of the measurement.

Conclusion: The results indicate that there is a convergence between the instruments, especially between overlapping dimensions, lending support to the validity of both measures. E-QALY project measure helped to identify some ceiling effects and lack of content coverage on the EQ-5D-5L, which suggests the E-QALY project measure may have greater validity in certain conditions.