Comparing the performance of the EQ-5D-3 L and the EQ-5D-5 L in an elderly Chinese population

Background: This study was conducted to compare the validity and discriminative power of both the EQ-5D-3 L and EQ-5D-5 L in an elderly Chinese population with multiple chronic and acute conditions.

Methods: A total of 648 retired people from China (mean ± standard deviation: 73.3 ± 6.4 years; male: 55.7%) were recruited and randomized to complete the 3 L or 5 L questionnaire. The 3 L and 5 L were compared in terms of distribution properties, ceiling effects, informativity, validity and discriminatory performance. Convergent validity between the 3 L and 5 L was tested by spearman's rank-order correlation. Discriminatory power was conducted by relative efficiency as assessed by the F statistics.

Results: Most participants answered to "no problems" on both versions of EQ-5D. The 5 L trended towards a slightly lower ceiling compared with the 3 L. The Shannon index improved with the 5 L while the Shannon's Evenness index tended to be similar. Convergent validity was confirmed by the moderate to strong correlation for both 3 L and 5 L. Relative efficiency suggested that 5 L had a higher absolute discriminatory power than the 3 L version in terms of the presence conditions, especially for osteoporosis and metabolic syndrome.

Conclusions: Both the 3 L and 5 L are demonstrated to be valid based HRQoL instruments in Chinese elderly population. The 5 L system may be preferable to the 3 L, as it demonstrated superior performance with respect to lower ceiling effect and better discriminatory power. Further research is needed to examine the responsiveness of the two EQ-5D instruments in this population.