The visual analogue scale (VAS) is a

psychometric Psychometrics is a field of study within psychology concerned with the theory and technique of measurement. Psychometrics generally refers to specialized fields within psychology and education devoted to testing, measurement, assessment, and ...

response scale that can be used in

questionnaire A questionnaire is a research instrument that consists of a set of questions (or other types of prompts) for the purpose of gathering information from respondents through survey or statistical study. A research questionnaire is typically a mix ...

s. 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 indicating a position along a continuous line between two end points. __TOC__

Comparison to other scales

This continuous (or "analogue") aspect of the scale differentiates it from discrete scales such as the

Likert scale A Likert scale ( , commonly mispronounced as ) is a psychometric scale commonly involved in research that employs questionnaires. It is the most widely used approach to scaling responses in survey research, such that the term (or more fully the ...

. There is evidence showing that visual analogue scales have superior metrical characteristics than discrete scales, thus a wider range of statistical methods can be applied to the measurements. The VAS can be compared to other linear scales such as the

Borg scale The Borg are an alien group that appear as recurring antagonists in the ''Star Trek'' fictional universe. The Borg are Cyborg, cybernetic organisms (cyborgs) linked in a Group mind (science fiction), hive mind called "the Collective". The Borg ...

. The sensitivity and reproducibility of the results are broadly very similar, although the VAS may outperform the other scales in some cases. These advantages extend to measurement instruments made up from combinations of visual analogue scales, such as semantic differentials.

Uses

Recent advances in methodologies for Internet-based research include the development and evaluation of visual analogue scales for use in Internet-based

s. VAS is the most common pain scale for quantification of

endometriosis Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, fa ...

-related pain and skin graft donor site-related pain. A review came to the conclusion that VAS and numerical rating scale (NRS) were the best adapted pain scales for pain measurement in endometriosis. For research purposes, and for more detailed pain measurement in clinical practice, the review suggested use of VAS or NRS for each type of typical pain related to endometriosis (

dysmenorrhea Dysmenorrhea, also known as period pain, painful periods or menstrual cramps, is pain during menstruation. Its usual onset occurs around the time that menstruation begins. Symptoms typically last less than three days. The pain is usually in th ...

, deep

dyspareunia Dyspareunia ( ) is painful sexual intercourse due to medical or psychological causes. The term ''dyspareunia'' covers both female dyspareunia and male dyspareunia, but many discussions that use the term without further specification concern the ...

and non-menstrual

chronic pelvic pain Pelvic pain is pain in the area of the pelvis. Acute pain is more common than chronic pain. If the pain lasts for more than six months, it is deemed to be chronic pelvic pain. It can affect both the male and female pelvis. Common causes in inclu ...

), combined with the clinical global impression (CGI) and a

quality of life Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards ...

scale. VAS is being increasingly used for the assessment of loudness and annoyance of acute and chronic tinnitus. The usage of a visual analogue scale (VAS) measuring fear of birth (FOB) was first initiated by Rouhe et al. FOBS is used to identify pregnant women with a fear of birth (FOB). It is a visual analogue scale (like VAS) that cover two constructs: worry and fear. The pregnant women are asked to rate their feelings about the approaching birth by responding to the question “How do you feel right now about the approaching birth?” on a paper with two 100 mm VAS-scale printed on it. They indicate their feeling and respond by placing a mark on the lines with the anchor words “calm/worried” and “no fear/strong fear”. The two values on the VAS-scales are added up to give a total score ranging from 0 to 100. Higher scores indicate higher levels of fear and the cut-off point for fear of birth is 60. Later on, FOBS, was then developed and tested based on Rouhe’s research in pregnant women in both Sweden and Australia. There have also been studies on pregnant women's thoughts when assessing fear of birth on the Fear of Birth Scale.

References

{{Pain Market research Pain management Psychometrics