Measurement properties of the Rajka-Langeland severity score in children and adults with atopic dermatitis

Abstract

Background: Multiple atopic dermatitis (AD) severity scales exist, with no gold standard for use in clinical practice.

Objectives: To determine the measurement properties of the Rajka-Langeland score and compare it with other clinician-reported outcomes in adults and children with AD.

Methods: We performed a prospective dermatology practice-based study using questionnaires and evaluation by a dermatologist (n = 427).

Results: Rajka-Langeland had good concurrent validity with the Eczema Area and Severity Index (Spearman rho = 0·63), SCORing AD (SCORAD) (rho = 0·61), objective-SCORAD (rho = 0·52) and body surface area (rho = 0·51); good convergent validity with the numeric rating scale average-itch (rho = 0·60) and worst-itch (rho = 0·59), Patient-Oriented Eczema Measure (rho = 0·57), Dermatology Life Quality Index (rho = 0·53), Patient-Reported Outcomes Measurement Information System Itch Questionnaire (rho = 0·35-0·55) in adults and/or children; fair discriminant validity for patient- and physician-reported global AD severity; good responsiveness to change of severity of AD and itch; good reliability; internal consistency; with no floor or ceiling effects. Interpretability bands (3, clear/almost clear; 4-5, mild; 6-7, moderate; 8-9, severe) and minimal clinically important difference (1 point) were established.

Conclusions: The Rajka-Langeland score showed good construct validity, reliability, internal consistency and responsiveness in adults and children with AD.