Validation of Labeled Magnitude Scale (LMS) for chronic pruritus

• Conditions: L29.9; Pruritus, unspecified

• Registration Number: DRKS00013074
• Lead Sponsor: Kompetenzzentrum chronischer Pruritus (KCP) und Klinik für Hautkrankheiten Universitätsklinikum Münster

Brief Summary

Introduction: The visual analogue scale (VAS), the numerical rating scale (NRS), and the verbal rating scale (VRS) are routinely used to assess pruritus intensity. However, these scales have limitations, especially the ceiling effect of linear scales (VAS, NRS) and the reduced sensitivity to change of the VRS. In the labeledmagnitude scale (LMS) consisting of a vertical line with verbal anchors distributed quasilogarithmically, the ceiling effect is reduced, allowing a higher discriminative assessment at the higher end of the scale. Methods: A total of 172 patients completed the LMS twice within 30–60 minutes to assess the reliability of the scale, as well as the NRS and VAS for analyses of convergent validity. Sensitivity to change of the LMS was investigated by analyzing changes in scores after a twice-daily application of an emollient containing menthoxypropanediol for 14 days. Results: Test-retest reliability was excellent for the LMS assessing average (Cronbach a: 0.955) and worst (Cronbach a: 0.945) pruritus intensity in the last 24 hours, while strong to very strong correlations were observed between the LMS and NRS assessing the worst (r=0.783) and average (r=0.808) pruritus intensity, respectively. Treatment with an emollient lead to a significant decrease in LMS scores (P<0.01). In patients with severe pruritus at baseline (VRS =3), we recorded a 30.2% improvement of average pruritus intensity using the LMS compared with a 25.0%improvement using theNRS and a 27.8%improvement ofworst pruritus intensity using the LMS compared with an 11.1%improvement with the NRS.Most patients considered the LMS an appropriate instrument to assess pruritus intensity (89.6%) and would use it again (91.9%). Discussion: The LMS is an appropriate well-accepted instrument to assess CP. It is especially useful to detect variations in pruritus intensity in patients with severe CP. Keywords: Labeled magnitude scale, Numerical rating scale, Visual analogue scale, Verbal rating scale, Chronic pruritus, Itch intensity

Detailed Description

Not available

Study Timeline

• Study Start: 2017-09-22
• Study Completion: 2018-11-23
• Results First Posted: 2021-09-13
• Last Update Posted: 19 August 2024

Recruitment & Eligibility

• Status: Complete
• Sex: All
• Target Recruitment: 179

Inclusion Criteria

Patients with chronic pruritus (L29.9), pruritus intensity NRS (0-10) max. past 24h =3

Exclusion Criteria

Patients under 18 years of age; -acute exacerbation of dermatosis, cutaneous infections
- pregnancy or lactation
-anamnestic drug consumption, alcohol dependency, drug abuse

Exclusion criteria in patients with additional planned skin biopsy:
- Allergy to local anesthetics,
-inclination to keloids

Study & Design

• Study Type: observational
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Validation of LMS (Labeled Magnitude Scale) in chronic pruritus via correlation with the already validated pruritus intensity scales (visual analogue scale, numerical rating scale, verbal rating scale), correlation with restriction of the quality of life (measured by ItchyQoL, DLQI, 5PLQ), retest analyzes of LMS on day 1 t=0 and t=30-60min

Secondary Outcome Measures

Name	Time	Method
Analysis of the change sensitivity of the LMS from day 1 and day 14, correlation of the LMS with the density of intraepidermal nerve fibers on day 1 and day 14.