The visual analogue scale or visual analog scale (VAS) 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 indicating a position along a continuous line between two end-points.
Comparison to other scales
This continuous (or “analogue”) aspect of the scale differentiates it from discrete scales such as the Likert scale. 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 Likert scale or Borg scale. 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.
Recent advances in methodologies for Internet-based research include the development and evaluation of visual analogue scales for use in Internet-based questionnaires.
VAS is the most common pain scale for quantification of endometriosis-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, deep dyspareunia and non-menstrual chronic pelvic pain), combined with the clinical global impression (CGI) and a quality of life scale. VAS is being increasingly used for the assessment of loudness and annoyance of acute and chronic tinnitus.
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- ^Grant, S.; Aitchison, T.; Henderson, E.; Christie, J.; Zare, S.; McMurray, J.; Dargie, H. (1999). “A comparison of the reproducibility and the sensitivity to change of visual analogue scales, Borg scales, and Likert scales in normal subjects during submaximal exercise”. Chest. 116 (5): 1208–17. doi:10.1378/chest.116.5.1208. PMID 10559077.
- ^Funke, F; Reips, U.-D. (2012). “Why semantic differentials in Web-based research should be made from visual analogue scales and not from 5-point scales” (PDF). Field Methods. 24: 310–327. doi:10.1177/1525822X12444061.
- ^-D. Reips (2006) Web-based methods. In M. Eid & E. Diener (Eds.), Handbook of multimethod measurement in psychology(pp. 73-85). Washington, DC: American Psychological Association. doi:10.1037/11383-006
- ^Sinha S, Schreiner AJ, Biernaskie J, Nickerson D, Gabriel VA (June 2017). “Treating pain on skin graft donor sites: review and clinical recommendations”. J Trauma Acute Care Surg. doi:10.1097/TA.0000000000001615. PMID 28598907.
- ^Bourdel, N.; Alves, J.; Pickering, G.; Ramilo, I.; Roman, H.; Canis, M. (2014). “Systematic review of endometriosis pain assessment: how to choose a scale?”. Human Reproduction Update. 21 (1): 136–152. doi:10.1093/humupd/dmu046. ISSN 1355-4786. PMID 25180023.
- ^Adamchic, I; Langguth, B; Hauptmann, C; Tass, PA (2012). “Psychometric evaluation of visual analog scale for the assessment of chronic tinnitus”. American Journal of Audiology. 21: 215–225. doi:10.1044/1059-0889(2012/12-0010).