Estimating the relationship between EQ-5D-5L and EQ-5D-3L

It has been shown that the EQ5D-3L and EQ5D-5L are likely to give very different values to changes in health. Therefore, 3L and 5L cannot be used interchangeably if consistency in decision making is required. This raises several important challenges, one of which is the need to be able to translate reliably from one instrument to the other.

Whilst there are current estimates linking 3L and 5L responses and values (see notes 1 and 2 below), these estimates are limited by the underlying data which come from two sources. They are vastly underpowered, do not span relevant populations and it is unknown whether the degree of separation between 3L and 5L questions is sufficient.

There is a need for a reference case mapping approach, given the likely need to link 3L and 5L for decades to come. This need was also recognised by NICE in their interim position statement on the use of 5L.

Notes:

1. Hernandez, M. and Pudney, S. (2017) Econometric modelling of multiple self-reports of health states: the switch from EQ-5D-3L to EQ-5D-5L in evaluating drug therapies for rheumatoid arthritis, Journal of Health Economics, 55, pp. 139-152.

2. Van Hout, B., Janssen, M. F., Feng, Y. et al. (2012) Interim scoring for the EQ-5D-5L: mapping the EQ-5D-5L to EQ-5D-3L value sets, Value in Health, 15, pp. 708-15.