Visual Analogue Scale (VAS)
The VAS is a scale consisting of a 10cm long line and a single question. Along with the NRS, it is most commonly used in clinical trials for measuring itch intensity and features high reliability and concurrent validity. The left end point represents “no itch” and the right end point the “worst imaginable itch”.
It can be interpreted as follows:  VAS 0= no pruritus
                                                            VAS < 3= mild pruritus
                                                            VAS ≥ 3-<7= moderate pruritus
                                                            VAS ≥ 7-<9 = severe pruritus
                                                            VAS ≥ 9= very severe pruritus
  • Time needed for completion: 1 minute
References:
  • Reich A, Chatzigeorkidis E, Zeidler C, Osada N, Furue M, Takamori K, Ebata T, Augustin M, Szepietowski JC, Ständer S. Tailoring the Cut-off Values of the Visual Analogue Scale and Numeric Rating Scale in Itch Assessment. Acta Derm Venereol. 2017 Jun 9;97(6):759-760.

  • Reich A, Riepe C, Anastasiadou Z, M?drek K, Augustin M, Szepietowski JC, Ständer S. Itch assessment with visual analogue scale and numerical rating scale: determination of minimal clinically important difference in chronic itch. Acta Derm Venereol 2016; 96: 978–980.
 
  • Kido-Nakahara M, Katoh N, Saeki H, Mizutani H, Hagihara A, Takeuchi S, et al. Comparative cut-off value setting of pruritus intensity in visual analogue scale and verbal rating scale. Acta Derm Venereol 2015; 95: 345–346.
 
  • Furue M, Ebata T, Ikoma A, Takeuchi S, Kataoka Y, Takamori K, et al. Verbalizing extremes of the visual analogue scale for pruritus: a consensus statement. Acta Derm Venereol 2013; 93: 214–215.
 
  • Phan NQ, Blome C, Fritz F, Gerss J, Reich A, Ebata T, et al. Assessment of pruritus intensity: prospective study on validity and reliability of the visual analogue scale, numerical rating scale and verbal rating scale in 471 patients with chronic pruritus. Acta Derm Venereol 2012; 92: 502–507.
 
  • Reich A, Heisig M, Phan NQ, Taneda K, Takamori K, Takeuchi S, et al. Visual analogue scale: evaluation of the instrument for the assessment of pruritus. Acta Derm Venereol 2012; 92: 497–50.
​​
  • ​Storck M, Sandmann S, Bruland P, Pereira MP, Steinke S, Riepe C, Soto-Rey I, Garcovich S, Augustin M, Blome C, Bobko S, Legat FJ, Potekaev N, Lvov A, Misery L, Weger W, Reich A, Şavk E, Streit M, Serra-Baldrich E, Szepietowski JC, Dugas M, Ständer S, Zeidler C. Pruritus Intensity Scales across Europe: A Prospective Validation Study. J Eur Acad Dermatol Venereol. 2021 Jan 7.