Quality control

Version numbering

The EuroQol Office is actively improving the sustainability of our EQ-5D products through continuous life cycle management procedures. As we want our users to be able to check if they have the most up-to-date version of EQ-5D, a new version numbering system was introduced in October 2014 for all EQ-5D language versions.

Version 1.0

Since the introduction of the new version numbering system in October 2014 all products available in the system have been reviewed for consistency in formatting and are labelled version 1.0.

Changes to version numbers

Version numbers will change when modifications are made. Changes are classified either as ‘major’ or ‘minor’.

Major changes

Major changes to an EQ-5D language version are changes that potentially could affect responses on the instrument. For example a change to the wording within a dimension or to the VAS labels or instructions. Experience has shown that major changes occur very infrequently, but occasionally are required. Any major changes will be released immediately.
Note that when a major change is made to an EQ-5D language version, the version number will increase in the first digit, i.e. v1.0 will become v2.0.

Minor changes

Minor changes to an EQ-5D language version are changes that are not expected to affect responses on the instrument. Examples are changes in layout or corrections in grammar or punctuation.
Minor changes to an EQ-5D language version will be reflected by a change in the second digit of the version number, i.e. v2.0 will become v2.1.

Impact on current studies and users

The introduction of our version numbering system, as described above, has no impact on the results of currently ongoing studies, or how EQ-5D language versions can be used.

New Studies

When starting a new study we advise EQ-5D users to check if they have the latest versions of the required EQ-5D language versions. Alternatively, please contact the EuroQol Office.

If necessary, a member of the Office team can provide you with the latest versions.

Release of new EQ-5D language versions

Note that major changes to EQ-5D language versions will be released when the changes are approved.

What to do when an error is found in the EQ-5D

We apply a rigorous standard for the production of EQ-5D translations and adaptions. However, it is good to note that some translations were prepared more than 10 years ago, which could mean, in some cases, that the EQ-5D wording is not optimal, or is outdated. If you think that you have detected a possible error or inconsistency, please contact the EuroQol Office. A member of the EuroQol Office team will contact you for further details.

For further information please visit our Frequently Asked Questions.