EQ-5D
Encyclopedia
EQ-5D is a standardised measure of health status developed by the EuroQol Group in order to provide a simple, generic measure of health
for clinical and economic appraisal. Applicable to a wide range of health conditions and treatments, it provides a simple descriptive profile and a single index value for health status that can be used in the clinical and economic evaluation of health care
as well as in population health surveys.
EQ-5D is designed for self-completion by respondents and is ideally suited for use in postal surveys, in clinics, and in face-to-face interviews. It is cognitively undemanding, taking only a few minutes to complete. Instructions to respondents are included in the questionnaire.
, self-care
, usual activities, pain
/discomfort
and anxiety
/depression. Each dimension has 3 levels: no problems, some problems, extreme problems. The respondent is asked to indicate his/her health state by ticking (or placing a cross) in the box against the most appropriate statement in each of the 5 dimensions. The EQ VAS records the respondent’s self-rated health on a vertical, visual analogue scale
where the endpoints are labelled ‘Best imaginable health state’ and ‘Worst imaginable health state’. This information can be used as a quantitative measure of health outcome as judged by the individual respondents.
The EQ-5D-3L has now been translated into more than 150 languages and is used worldwide. However ceiling effect
s have been reported, particularly when used in general population surveys but also in some patient population settings. In order to address these criticisms, and encouraged by demand from clinicians and other users, the EuroQol Group decided to explore ways of improving the EQ-5D’s measurement properties.
and potentially reducing ceiling effects. The Group therefore decided that the new version of the EQ-5D should include five levels of severity in each of the existing five EQ-5D dimensions and that it would be called the EQ-5D-5L. The existing EQ-5D will be renamed the EQ-5D-3L.
The EQ-5D-5L still consists of 2 pages – the EQ-5D-5L descriptive system (page 2) and the EQ visual Analogue scale (EQ VAS) (page 3) plus a cover page. The descriptive system comprises the same 5 dimensions as the EQ-5D-5D-3L (mobility, self care, usual activities, pain/discomfort, anxiety/depression). However, each dimension now has 5 levels: no problems, slight problems, moderate problems, severe problems, and extreme problems. The respondent is asked to indicate his/her health state by ticking (or placing a cross) in the box against the most appropriate statement in each of the 5 dimensions. This decision results in a 1-digit number expressing the level selected for that dimension. The digits for 5 dimensions can be combined in a 5-digit number describing the respondent’s health state. It should be noted that the numerals 1-5 have no arithmetic
properties and should not be used as a cardinal score. During the development of the EQ-5D-5L, the opportunity was also taken to improve some of the wording in the dimensions to enhance consistency and facilitate understanding. For example, the old wording of ‘confined to bed’ to indicate the upper extreme in the EQ-5D-3L has been replaced with ‘I am unable to walk about’ which is more consistent with the wording within the Mobility dimension and with the extreme levels on other dimensions.
The EQ VAS records the respondent’s self-rated health on a 20 cm vertical, visual analogue scale with endpoints labelled ‘the best health you can imagine’ and ‘the worst health you can imagine’. This information can be used as a quantitative measure of health as judged by the individual respondents. The instructions for the EQ VAS task have been changed and simplified in the EQ-5D-5L. The EuroQol Group had received feedback over the years that respondents sometimes found it difficult to draw a line from the box to the scale. It was also cumbersome for administrators to record their scores. The EQ-5D-5L now asks respondents to simply ‘mark an X on the scale to indicate how your health is TODAY’ and then to ‘write the number you marked on the scale in the box below’. This should make the task easier for both respondents and users.
Health
Health is the level of functional or metabolic efficiency of a living being. In humans, it is the general condition of a person's mind, body and spirit, usually meaning to be free from illness, injury or pain...
for clinical and economic appraisal. Applicable to a wide range of health conditions and treatments, it provides a simple descriptive profile and a single index value for health status that can be used in the clinical and economic evaluation of health care
Health care
Health care is the diagnosis, treatment, and prevention of disease, illness, injury, and other physical and mental impairments in humans. Health care is delivered by practitioners in medicine, chiropractic, dentistry, nursing, pharmacy, allied health, and other care providers...
as well as in population health surveys.
EQ-5D is designed for self-completion by respondents and is ideally suited for use in postal surveys, in clinics, and in face-to-face interviews. It is cognitively undemanding, taking only a few minutes to complete. Instructions to respondents are included in the questionnaire.
EQ-5D-3L
The EQ-5D 3 level version (EQ-5D-3L) was introduced in 1990. The EQ-5D-3L essentially consists of 2 pages - the EQ-5D descriptive system (page 2) and the EQ visual analogue scale (EQ VAS) (page 3) plus a cover page. The EQ-5D-3L descriptive system comprises the following 5 dimensions: mobilityMobility
Mobility may refer to:* Mobility * "Mobiliy" , a song by Moby* Mobility * Mobility , the ability of military units or weapon systems to move to an objective-See also:* Academic mobility* Apprentices mobility...
, self-care
Self-care
Self care is personal health maintenance. It is any activity of an individual, family or community, with the intention of improving or restoring health, or treating or preventing disease....
, usual activities, pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
/discomfort
Discomfort
Discomfort may refer to:* Pain, an unpleasant sensation* Suffering, an experience of unpleasantness...
and anxiety
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
/depression. Each dimension has 3 levels: no problems, some problems, extreme problems. The respondent is asked to indicate his/her health state by ticking (or placing a cross) in the box against the most appropriate statement in each of the 5 dimensions. The EQ VAS records the respondent’s self-rated health on a vertical, visual analogue scale
Visual Analogue Scale
A visual analogue scale is a psychometric response scale which can be used in questionnaires. It is a measurement instrument for subjective characteristics or attitudes that cannot be directly measured. When responding to a VAS item, respondents specify their level of agreement to a statement by...
where the endpoints are labelled ‘Best imaginable health state’ and ‘Worst imaginable health state’. This information can be used as a quantitative measure of health outcome as judged by the individual respondents.
The EQ-5D-3L has now been translated into more than 150 languages and is used worldwide. However ceiling effect
Ceiling effect
The term ceiling effect has two distinct meanings, referring to the level at which an independent variable no longer has an effect on a dependent variable, or to the level above which variance in an independent variable is no longer measured or estimated...
s have been reported, particularly when used in general population surveys but also in some patient population settings. In order to address these criticisms, and encouraged by demand from clinicians and other users, the EuroQol Group decided to explore ways of improving the EQ-5D’s measurement properties.
EQ-5D-5L
In 2005, a Task Force was established within the EuroQol Group to investigate methods to improve the instrument’s sensitivity and to reduce ceiling effects. After much discussion, the Task Force decided that there should be no change in the number of dimensions for a new version of EQ-5D. However, previously published studies by EuroQol Group members showed that experimental 5-level versions of EQ-5D could significantly increase reliability and sensitivity (discriminatory power) while maintaining feasibilityFeasibility
Feasibility may refer to:*Logical possibility, that which is achievable.*Feasible region, a region that satisfies mathematical constraints*Feasibility study, a preliminary study to determine a project's viability....
and potentially reducing ceiling effects. The Group therefore decided that the new version of the EQ-5D should include five levels of severity in each of the existing five EQ-5D dimensions and that it would be called the EQ-5D-5L. The existing EQ-5D will be renamed the EQ-5D-3L.
The EQ-5D-5L still consists of 2 pages – the EQ-5D-5L descriptive system (page 2) and the EQ visual Analogue scale (EQ VAS) (page 3) plus a cover page. The descriptive system comprises the same 5 dimensions as the EQ-5D-5D-3L (mobility, self care, usual activities, pain/discomfort, anxiety/depression). However, each dimension now has 5 levels: no problems, slight problems, moderate problems, severe problems, and extreme problems. The respondent is asked to indicate his/her health state by ticking (or placing a cross) in the box against the most appropriate statement in each of the 5 dimensions. This decision results in a 1-digit number expressing the level selected for that dimension. The digits for 5 dimensions can be combined in a 5-digit number describing the respondent’s health state. It should be noted that the numerals 1-5 have no arithmetic
Arithmetic
Arithmetic or arithmetics is the oldest and most elementary branch of mathematics, used by almost everyone, for tasks ranging from simple day-to-day counting to advanced science and business calculations. It involves the study of quantity, especially as the result of combining numbers...
properties and should not be used as a cardinal score. During the development of the EQ-5D-5L, the opportunity was also taken to improve some of the wording in the dimensions to enhance consistency and facilitate understanding. For example, the old wording of ‘confined to bed’ to indicate the upper extreme in the EQ-5D-3L has been replaced with ‘I am unable to walk about’ which is more consistent with the wording within the Mobility dimension and with the extreme levels on other dimensions.
The EQ VAS records the respondent’s self-rated health on a 20 cm vertical, visual analogue scale with endpoints labelled ‘the best health you can imagine’ and ‘the worst health you can imagine’. This information can be used as a quantitative measure of health as judged by the individual respondents. The instructions for the EQ VAS task have been changed and simplified in the EQ-5D-5L. The EuroQol Group had received feedback over the years that respondents sometimes found it difficult to draw a line from the box to the scale. It was also cumbersome for administrators to record their scores. The EQ-5D-5L now asks respondents to simply ‘mark an X on the scale to indicate how your health is TODAY’ and then to ‘write the number you marked on the scale in the box below’. This should make the task easier for both respondents and users.