Worst Itch/Pruritus Numeric Rating Scale (WI‑NRS/WP‑NRS)

DESCRIPTION:
The Worst Itch Numeric Rating Scale is a single-item, patient-reported questionnaire that measures itch intensity, pruritus, over the past 24 hours. The scale ranges from 0 (no itch) to 10 (worst itch imaginable).¹

DISEASE STATES: 
Atopic dermatitis

VALIDATED USES: 
Assessment, screening, treatment monitoring

ADMINISTRATION METHOD:
Patient

COMMONLY USED IN:
Clinical trials, research, clinical practice

DETAILED DESCRIPTION:
The Worst Itch Numeric Rating Scale (WI-NRS), also referred to as the Peak Pruritus Numerical Rating Scale, was developed to provide a robust measurement of patient-reported itch intensity in moderate-to-severe AD. The WI-NRS is a monodimensional scale, which measures the subjective intensity of pruritus at a given period of time, the prior 24 hours.¹ In AD, daily itch can become a debilitating symptom and a substantial disease burden on the patient due to a reduced quality of life (QOL), disturbed sleep patterns, and low mental functioning.²

Patient-reported instruments, such as the WI-NRS, are often one of the most relevant tools to generate evidence that supports the assessment of treatment effects in clinical trials.³

PRURITIS NUMERIC RATING SCALE

On a scale of 0 (no itch) to 10 (worst imaginable itch), how would you rate your worst itch in the past 24 hours? Select a number.

Note: NRS 0 = no pruritus; NRS <3 = mild pruritus; NRS ≥3 to <7 = moderate pruritus; NRS ≥7 to <9 = severe pruritus; NRS ≥9 = very severe pruritus.

VALIDITY:

The WI-NRS demonstrates content validity for measuring worst itch in the past 24 hours. It has construct validity, it is sensitive to measuring change, and has excellent test-retest reliability.¹

LIMITATIONS:

Self-reported pruritus symptoms are subjective measures and interpreting WI-NRS may vary. The magnitude of the reduction in NRS scores that represents meaningful improvement for patients has not been universally established.⁴

This resource is intended for educational purposes only and is intended for US healthcare professionals. Healthcare professionals should use independent medical judgment. All decisions regarding patient care must be handled by a healthcare professional and be made based on the unique needs of each patient.

References: 1. Yosipovitch G, Reaney M, Mastey V, et al. Peak Pruritus Numerical Rating Scale: psychometric validation and responder definition for assessing itch in moderate-to-severe atopic dermatitis. Br J Dermatol. 2019;181(4):761-769. doi:10.1111/bjd.17744  2. Simpson EL, Bieber T, Eckert L, et al. Patient burden of moderate to severe atopic dermatitis (AD): Insights from a phase 2b clinical trial of dupilumab in adults. J Am Acad Dermatol. 2016;74(3):491-498. doi:10.1016/j.jaad.2015.10.043. 3. Kwatra SG, Yosipovitch G, Kim B, et al. Worst Itch Numeric Rating Scale for Prurigo nodularis: a secondary analysis of 2 randomized clinical trials. JAMA Dermatol. Published online June 12, 2024. doi:10.1001/jamadermatol.2024.1634 4.  Vernon MK, Swett LL, Speck RM, et al. Psychometric validation and meaningful change thresholds of the Worst Itching Intensity Numerical Rating Scale for assessing itch in patients with chronic kidney disease-associated pruritus. J Patient Rep Outcomes. 2021;134(5):1-12. doi:10.1186/s41687-021-00404-z