Validity and reliability of itch assessment scales for chronic pruritus in adults: A prospective multicenter study.
BACKGROUND
Several tools can provide a reliable and accurate evaluation of pruritus, including the visual analog scale (VAS), numeric rating scale (NRS), verbal rating scale (VRS), and multidimensional questionnaires such as the Itch Severity Scale (ISS). However, no single method is considered a gold standard.


OBJECTIVE
We evaluated the validity and reliability of VAS, NRS, VRS, and ISS and their correlation with a pruritus-specific quality of life instrument, ItchyQoL.


METHODS
A total of 419 patients (215 men and 204 women) with chronic pruritus (mean age, 46.58 years) recorded their pruritus intensity on VAS, NRS, VRS, and ISS. Retest reliability was analyzed in a second assessment 3 hours after the initial assessment. All participants answered ItchyQoL.


RESULTS
A strong correlation between VAS, NRS, and VRS was found. ISS showed a low intercorrelation validity with these tools. However, ISS was more strongly correlated with ItchyQoL. The retest reliability scores were similar for VAS, NRS, and VRS but lower than the scores obtained for ISS.


LIMITATIONS
Limitations include patient heterogeneity and recall bias.


CONCLUSION
The assessment of pruritus is challenging because of the subjective symptoms and the multifactorial nature. Therefore, more studies are needed to determine the best strategy to assess itch intensity.
['Jang|Yong Hyun|YH|', 'Kim|Seok Min|SM|', 'Eun|Dong Hyuk|DH|', 'Park|Kyung Duck|KD|', 'Park|Gyeong-Hun|GH|', 'Kim|Byung-Soo|BS|', 'Li|Kapsok|K|', 'Park|Chang Ook|CO|', 'Kim|Hye One|HO|', 'Kim|Hei Sung|HS|', 'Jang|Min Soo|MS|', 'Doh|Eun Jin|EJ|', 'Lee|Dong Hun|DH|', 'Lee|Yang Won|YW|', 'Kim|Do Won|DW|', 'Kim|Seong-Jin|SJ|']
D000328:Adult D000367:Age Factors D002908:Chronic Disease D015331:Cohort Studies D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D011446:Prospective Studies D011537:Pruritus D011788:Quality of Life D015203:Reproducibility of Results D018570:Risk Assessment D012720:Severity of Illness Index D012737:Sex Factors D018434:Sickness Impact Profile D011795:Surveys and Questionnaires D064232:Visual Analog Scale
itch pruritus quality of life atopic dermatitis eczema urticaria