This document discusses the differences between the EQ-5D-3L and EQ-5D-5L health-related quality of life instruments. It notes that the 5L was developed to address concerns with the 3L, including reduced ceiling effects and better discrimination among patient subgroups. While the 3L is still commonly used, studies show the 5L provides improvements. A challenge is that switching between the 3L and 5L is likely to affect quality-adjusted life year (QALY) estimates and healthcare technology assessments. The sources of differences between the instruments relate to how patients respond to the questionnaires as well as how general public preferences are valued.

1. EQ-5D – 3L or 5L?
Professor Nancy J. Devlin

2. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain
The issue
■ For many years NICE has recommended use of the 3L, and its UK value set (Dolan
1997)
■ 5L available (Herdman et al 2011) with value sets eg. England (Devlin et al 2017)
■ In the UK: choice whether to use the 5L (and English value set) or the 3L (and UK
value set) likely to affect estimates of QALYs and ICERs.
- QoL increasing: QALY gains likely to be reduced (to varying degrees)
- LoL increasing: QALY gains likely to be increased (to varying degrees)
■ These differences create a challenge for NICE
- potential inconsistency between past/future HTA decisions
- Inconsistency between future decisions where some evidence based on the 3L,
and some based on 5L mapped to 3L values
■ Other countries may also face transitional issues
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3. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain
Sources of differences between the 3L and 5L
■ There are differences in both
■ The interaction between these determines the effect on QALYs
■ We have empirical evidence; and further studies underway.
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Measurement properties Valuation properties
How do patients respond to the
questionnaire?
What are the stated preferences of the
general public?

4. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain
3L vs 5L as measures of patient health
■ 5L was developed in response to concerns about the 3L.
■ Evidence shows that the 5L, compared to the 3L, has:
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Reduced ceiling effects Eg. Mukuria et al (2017); Janssen et al
(2013); Agborsayanga et al (2014); Feng et
al (2015);
Less ‘clustering’ of data on relatively few health
states
Eg. Parkin et al (2016); Zamora et al
(2017a); Feng et al (2016) ; Buccholz et al
(2017)*
Evidence of better discriminatory power among
patient subgroups
Eg. Janssen et al (2017)*; Pan et al (2015);
Wang et al (2016).
Important improvements in the 5L with respect to
problems with mobility
Eg. Janssen et al (2017)*

5. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain
EQ-5D-3L value set EQ-5D-5L crosswalk EQ-5D-5L value set
% health states worse than dead 34.6% 26.7% 5.1%
Dimension importance order Pain/Discomfort
Mobility
Anxiety/depression
Self-care
Usual Activities
Pain/Discomfort
Mobility
Anxiety/Depression
Self-care
Usual Activities
Pain/Discomfort
Anxiety/depression
Mobility
Self-care
Usual Activities
Health state values
‘Mildest’ state (11211) 0.883 0.906 0.950 (11211/12111)
‘Moderate’ state (22222 (3L) or
33333 (5L))
0.516 0.516 0.593
‘Worst’ state (33333 (3L) or
55555 (5L))
-0.594 -0.594 -0.285
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Comparing 3L(UK) and 5L(England) value sets
Source: Mulhern et al (2017)

6. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain
Comparing 3L(UK) and 5L(England) value sets
■ The ‘bi-modal’ nature of
the UK 3L value set values
is not present in the
England 5L values.
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0
.5
1
1.5
2
Density
-.5 0 .5 1
Utility value
EQ-5D-5L EQ-5D-3L
Crosswalk
Source: Mulhern et al (2017)

7. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain7 21-22 September 2017
Comparing EQ-3L Index and EQ-5L Index data
EQ Index = Patients’ EQ-5D profile data to which the value set has been applied
Source: Parkin, Devlin, Feng (2016) Medical
Decision Making
“non-normal distributions of 3L data,
featuring two distinct groups, are
commonly observed…this is a result of
the classification system…the UK 3L
value set exacerbates this by placing a
larger weight on level 3 observations”

8. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain
Distributions of the EQ Index applying the van
Hout mapping vs England 5L value set.
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Note: these two diagrams both use the same NHS data set of 5L profile data reported
by patients.

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Issues with relying on the van Hout mapping
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The evaluation space between 0.5 to 1.0 – where most people are – includes only 31
health states in the 3L. In the 0.8-1.0 space the situation is even worse
- The van Hout mapping allows
5L data to be valued using the
3L UK value set (so has all the
problems of the latter)
PLUS
- Discontinuities in the
distribution attributable to the
mapping function (this issue is
not specific to the UK/England)

10. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain
Reasons which apply to all countries Reasons specific to the UK/England
Difference in the preference elicitation tasks
eg. improved TTO procedure for obtaining
values < 0; inclusion of DCE tasks
There is a 20 year gap between the stated
preference data collected. The composition of
the general public and their preferences may
have changed
A different instrument is being valued eg.
mobility level 5 is descriptively different from
mobility level 3 in the 3L.
The UK 3L value set is unusual in various
respects eg. high % values < 0; ‘two-group’
distribution of values. Any new value set,
whether for 3L or 5L, unlikely to replicate its
properties.
Differences in modelling approaches Innovative modelling: heterogeneity;
heteroscedasticity; hybrid; ‘censoring’
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Why are 3L and 5L values different?

11. www.euroqol.org34th EuroQol Plenary Meeting 2017 – Barcelona, Spain
Is the UK 3L value set the ‘odd one out’..?
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■ 1998 UK ‘replication study’ (Kind & Macran 1999)
■ Values systematically higher than the UK 3L value set
■ Similar findings reported in Tsuchiya et al (2006)
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1
MVH (1993)
York(1998)
UK 3L UK replication England 5L
Value for ‘pits’ -0.594 -0.126 -0.285
% states < 0 34.6% 12.3% 5.1%
Value for ‘middle’ state 0.516 0.616 0.593

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Concluding remarks
■ Evidence points to the 5L being a better descriptive system than the 3L: it more
accurately describes patients’ health.
■ The value sets for the 5L are based on more up to date preference data, and draw on
improvements in methods developed over the last 20 years
■ 5L value sets are different than the 3L value sets: this doesn’t mean that there is a
‘problem’ with the 5L that needs to be ‘fixed’
■ Mulhern et al (2017): ‘QALYs may have been overestimated using the UK 3L value set’.
■ England 5L value set (correctly, given implications for NICE) subject to external
validation
■ But the UK 3L value set which continues to be used was never subject to that scrutiny.
■ The transitional challenge facing NICE is inevitable in shifting to any new preference-
based measure
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13. For more information, contact
ndevlin@ohe.org