EQ-5D Nomenclature

The following is a clarification of the EQ-5D nomenclature. The purpose is to define standards for the naming of concepts used in describing the EQ-5D and data produced by the EQ-5D. This forms part of a wider task of defining standards for the reporting of the EQ-5D. The advantages of a standard nomenclature are in the comprehension by people of what information about the EQ-5D means. First there should be a clear distinction between the questionnaire designed to measure health status (EQ-5D) and the questionnaire designed to collect valuations for health states defined by the EQ-5D. EQ-5D self-report questionnaire (designed to measure health status).

Term

Description

EQ-5D-3L

Descriptive system of health-related quality of life states consisting of five dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) each of which can take one of three responses. The responses record three levels of severity (no problems/some or moderate problems/extreme problems) within a particular EQ-5D dimension.

EQ-5D-5L

Descriptive system of health-related quality of life states consisting of five dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) each of which can take one of five responses. The responses record five levels of severity (no problems/slight problems/moderate problems/severe problems/extreme problems) within a particular EQ-5D dimension.

EQ-5D-Y

EQ-5D-Y Youth version. Descriptive system of youth health-related quality of life states consisting of five dimensions (mobility, looking after myself, doing usual activities, having pain or discomfort, feeling worried, sad or unhappy) each of which can take one of three responses. The responses record three levels of severity (no problems/some problems or a bit/a lot (of) problems or very) within a particular EQ-5D dimension.

EQ-5D descriptive system

Standard layout for the above five-dimensional descriptive system, for recording an individual’s current EQ-5D self-reported health state (often referred to as page 2 of the EQ-5D questionnaire)

EQ-5D self-reported health state

An EQ-5D health state recorded by an individual on the EQ-5D descriptive system.

EQ VAS

Standard vertical 20 cm visual analogue scale (similar to a thermometer) for recording an individual’s rating for their current health-related quality of life state (often referred to as page 3 of the EQ-5D questionnaire)

EQ VAS score

Score recorded by an individual for their current health-related quality of life state on the EQ VAS

EQ SDQ

Standard set of questions concerning socio-demographic variables for use with the EQ-5D valuation questionnaire and a modified version for use with the EQ-5D questionnaire. NB These questions are optional for users.

EQ-5D self-report questionnaire

Questionnaire, of standard layout, consisting of the EQ-5D descriptive system, the EQ VAS and (if required) the modified version of the EQ SDQ.

 

EQ-5D valuation questionnaire (designed to collect valuations for health states defined by the EQ-5D)

Term

Description

EQ-5D health state

A health-related quality of life state profile described by the EQ-5D.

EQ-5D VAS

Visual analogue scale, of standard layout, for recording an individual’s ratings of EQ-5D health states.  The health states are expressed as a set of five statements, containing one response within each dimension of the EQ-5D.

EQ-5D VAS score

Score recorded by an individual for an EQ-5D health state on the EQ-5D VAS

EQ-5D valuation questionnaire

Questionnaire, of standard layout, consisting of the EQ-5D questionnaire (including full EQ SDQ) plus the EQ-5D VAS, and a standard set of instructions.

EQ-5D index

Index value attached to an EQ-5D state according to a particular set of weights.  It may be distinguished by a unique descriptor assigned by the creators of the weights, for example YMA1 EQ-5Dindex might be a value assigned according to the York MVH A1 value set.