Measuring outcomes for loneliness research: examining the appropriateness of the EQ-5D-5 L and EQ-HWB

Loneliness is a recognized global public health concern and significantly impacts overall well-being. This study aims to determine utility values associated with different loneliness levels and assess the performance of the EQ-5D-5D and EQ-HWB measures in capturing loneliness. Data from an online survey comprising a nationally representative cross-sectional sample of Australian adults was used. The survey included information on demographics, the 20-item Revised UCLA Loneliness Scale (R-UCLA-RS), EQ-5D-5 L, and EQ-HWB. The Kruskal-Wallis test was used to assess the statistical differences in utility scores from the EQ-5D-5 L and EQ-HWB-9, as well as the EQ-HWB sum score, across three levels of loneliness (Low/Medium/High) as measured by the R-UCLA-LS. Exploratory factor analysis (EFA) was used to explore the conceptual overlap between the EQ-5D-5 L and EQ-HWB with the R-UCLA-LS item measure. Additionally, ordinary least squares (OLS) regression was conducted to identify predictors of loneliness from the items that overlapped with the R-UCLA-LS.v 2072 respondents completed the survey. Both the EQ-5D-5 L and EQ-HWB measures significantly differentiated between loneliness levels (p < 0.001). The mean EQ-5D-5 L utility scores were 0.89 for low loneliness, 0.81 for moderate loneliness, and 0.72 for moderate to high loneliness. The EQ-HWB-9 utility scores were 0.88, 0.75, and 0.58, respectively, showing greater sensitivity to the burden of loneliness. EFA revealed no overlap between EQ-5D-5 L items and the R-UCLA-LS, while five EQ-HWB items overlapped with the R-UCLA-LS, including the “feel lonely” item, which is also part of the EQ-HWB-9. Regression analysis explained 53.58% of the variance in loneliness scores (F(10, 1463) = 168.87, p < 0.001), with “feeling lonely” and “feeling unsupported” contributing most to the prediction. While the EQ-5D-5 L shows moderate sensitivity to loneliness, the EQ-HWB and EQ-HWB-9 demonstrate stronger associations with loneliness measures. The EQ-HWB-9, in particular, shows promise as a brief yet sensitive tool for capturing loneliness-related burden and may be especially useful in interventions targeting loneliness.