OBJECTIVES: The EQ-5D-5L and 15D are generic preference-accompanied health status measures with similar dimensions. In this study, we aim to compare the measurement properties of the EQ-5D-5L and 15D descriptive systems and index scores in a large general population sample.

METHODS: In August 2021, an online cross-sectional survey was conducted in a nationally representative adult general population sample in Hungary (n=1887). The EQ-5D-5L and 15D descriptive systems and index scores were compared in terms of ceiling and floor effects, informativity (Shannon’s evenness index), agreement, convergent validity and known-groups validity for 20 different chronic physical and mental health conditions. Danish value sets were used to compute index scores for both instruments.

RESULTS: Among the corresponding dimensions, both the ceiling and floor effects were smaller for the EQ-5D-5L in most dimension pairs (exceptions: EQ-5D-5L anxiety/depression vs. 15D distress for the floor effect, and EQ-5D-5L anxiety/depression vs. 15D depression for the ceiling effect). The 15D index scores showed smaller ceiling effect than the EQ-5D-5L (21% vs. 36%). The average informativity was better for the EQ-5D-5L dimensions (0.56 vs. 0.49). A strong correlation was found between the EQ-5D-5L and 15D index scores (r=0.671). In most cases, the EQ-5D-5L was able to better discriminate between healthy respondents and those with chronic diseases; however, the difference in relative efficiency was insignificant in 18/20 condition groups (exceptions: thyroid diseases and gastroesophageal reflux disease).

CONCLUSIONS: This is the first study to compare the measurement properties of the EQ-5D-5L and 15D in a general population sample. The EQ-5D-5L performs better than the 15D for most measurement properties. Our findings help to understand the differences between the EQ-5D-5L and 15D instruments and index scores and provide broad information for health economic evaluations and resource allocation decisions.