Determining Severity Strata for Three Atopic Dermatitis Patient-Reported Outcome Questionnaires: Defining Severity Score Ranges for the Worst Pruritus Numerical Rating Scale and the Atopic Dermatitis Symptom and Impact Scales (ADerm-SS and ADerm-IS)

Abstract

Introduction: Three patient-reported outcome (PRO) questionnaires-Worst Pruritus Numerical Rating Scale (WP-NRS), Atopic Dermatitis Symptom Scale (ADerm-SS), and Atopic Dermatitis Impact Scale (ADerm-IS)-were developed to assess the symptoms and impacts of atopic dermatitis (AD). Severity strata for these PROs are needed to aid in their interpretation.

Methods: Using data from a global, randomized, double-blind, placebo-controlled, phase 3 clinical trial (NCT03568318) of patients with moderate-severe AD (age ≥ 12 years), equipercentile linking analyses were conducted to define severity strata applying the Patient Global Impression of Severity as an anchor. Analyses were conducted separately for adults and adolescents, and then harmonized between the two age groups.

Results: The sample included 769 adults and 113 adolescents. For the WP-NRS, 0 was associated with absent, 1-2 with minimal, 3 with mild, 4-7 with moderate, and 8-10 with severe. For the ADerm-SS Skin Pain, 0 was associated with absent, 1 with minimal, 2 with mild, 3-6 with moderate, and 7-10 with severe. For ADerm-SS 7-Item Total Symptom Score (TSS-7), 0-1 was associated with absent, 2-11 with minimal, 12-22 with mild, 23-47 with moderate, and 48-70 with severe. For ADerm-IS Sleep, 0 was associated with absent, 1-3 with minimal, 4-6 with mild, 7-20 with moderate, and 21-30 with severe. For ADerm-IS Daily Activities, 0 was associated with absent, 1-2 with minimal, 3-7 with mild, 8-25 with moderate, and 26-40 with severe. For ADerm-IS Emotional State, 0 was associated with absent, 1-2 with minimal, 3-8 with mild, 9-22 with moderate, and 23-30 with severe.

Conclusions: These severity strata provide score interpretations of the WP-NRS, ADerm-SS, and ADerm-IS, translating these scores to simple and intuitive outcomes, which can inform clinical studies and clinical practice.

Trial registration number: NCT03568318.

Keywords: ADerm-IS; ADerm-SS; Atopic dermatitis; Patient-reported outcomes; Pruritus; Severity strata; Skin pain; Sleep.

© 2022. The Author(s).

Figures

Fig. 1

Target questionnaires and scores. aQuestionnaire items use a 0–10 numerical rating scale. bItem completed daily. cTo avoid repeated measurement of concepts potentially assessed by other instruments in clinical trials, the ADerm-SS TSS-7 was developed by summing items that assess concepts not measured by clinician-reported questionnaires. ADerm IS Atopic Dermatitis Impact Scale, ADerm-SS Atopic Dermatitis Symptom Scale, TSS-7 7-Item Total Symptom Score, WP-NRS Worst Pruritus Numerical Rating Scale

Fig. 2

Patient Global Impression of Severity categories used for defining severity strata. PGIS Patient Global Impression of Severity. Absent, light peach with grey text; Minimal, peach with grey text; Mild, orange with white text; Moderate, light red with white text; Severe, dark red with white text

Fig. 3

Severity strata anchored to collapsed Patient Global Impression of Severity categories (adults and adolescents and pooled). Severity strata are based on the collapsed PGIS. Absent, light peach with grey text; Minimal, peach with grey text; Mild, orange with white text; Moderate, light red with white text; Severe, dark red with white text. The Moderate stratum corresponds to PGIS of Moderate and Moderately severe; the Severe stratum corresponds to PGIS of Severe and Very severe. ADerm IS Atopic Dermatitis Impact Scale, ADerm-SS Atopic Dermatitis Symptom Scale, PGIS Patient Global Impression of Severity, TSS-7 7-Item Total Symptom Score, WP-NRS Worst Pruritus Numerical Rating Scale