Harmonisation

As the collection of EQ-5D versions has grown organically over the years, inevitably some variance in wording, layout and style was introduced. The VMC Harmonization project aims to eliminate unnecessary variation between EQ-5D versions and modes of administration (e.g. Self-complete Paper, Self-complete Digital, Interviewer-Administered etc.).

There are two guiding principles. First, the EQ-5D wording (instructions and descriptive system) should be consistent across versions and modes of administration. Second, only necessary variance should be maintained.

The Harmonisation project was announced at the EuroQol’s General Assembly Meeting in 2017. At the time the guiding principles were introduced and the new EuroQol design guidelines were updated. As part of the Harmonisation project the decision was made to:

• Capitalize the dimension headers of EQ-5D-3L;
• Replace the instructions of the Paper Self-complete versions of EQ-5D-3L by those of EQ-5D-5L;
• Replace the VAS of the Paper Self-complete versions of EQ-5D-3L by the VAS used in EQ-5D-5L.

Later it was decided that the existing Telephone- and Face-to-Face Interview versions should be replaced by a new Interviewer-Administered version that is suitable for all kinds of interview situations (face-to-face or telephone/ online). More recently, it was decided to replace the 3 device-specific Digital versions (PDA, Tablet and Laptop/Desktop) with one Digital version that is suitable for all digital devices.

VMC is currently reviewing sets of EQ-5D versions per country/language. It is expected that the Harmonisation project will continue as long as EQ-5D is used, as languages continue to evolve.