Development and Validation of a Patient-Reported Outcome Measure of the Impact of Chronic Hand Eczema on Health-Related Quality of Life: the Hand Eczema Impact Scale (HEIS).

Abstract

Chronic Hand Eczema (CHE) is an inflammatory skin disease that causes significant impact on health-related quality of life (HRQoL). The Hand Eczema Impact Scale (HEIS) is a new patient-reported outcome(PRO) measure designed to assess the impact of CHE on key domains of HRQoL. This study aimed to develop and evaluate content and psychometric validity of the HEIS. The HEIS was initially developed on the basis of a literature review and concept elicitation interviews. Qualitative cognitive debriefing interviews (n = 20) were conducted with patients with CHE to assess relevance and understanding of items, response options, and recall period. Psychometric properties (item performance, dimensionality, reliability, validity, responsiveness, and estimation of meaningful change thresholds) were then assessed using data (n = 258) from a phase 2b trial (NCT03683719). Cognitive debriefing confirmed all items were understood and relevant to patients. Inter-item correlations (all > 0.50) and confirmatory factor analysis (factor loadings ≥ 0.80) supported unidimensionality of the HEIS score, and mostly provided support for the HEIS Proximal Daily Activity Limitations (PDAL) score, with only one item loading below the prespecified threshold. Item properties and previous qualitative work supported retaining this item in the total score but removed from the HEIS PDAL domain. Internal consistency (Cronbach's alpha ≥ 0.89) and test-retest reliability (intra-class correlation coefficient ≥ 0.79) results were very strong. Strong correlations with concurrent measures (0.66-0.87) and significant differences between severity groups (p < 0.001) supported construct validity. Large effect sizes for mean change scores in participants that improved and significant differences between groups indicated ability to detect change. Anchor-based analyses supported within-individual responder definitions of ≥ 1.3 points for improvements in both HEIS score and HEIS PDAL score (covering three items) and of ≥ 1.5 points for HEIS embarrassment with the appearance of hands (Emb) score (covering two items). The 9-item HEIS is the first CHE-specific PROmeasure developed and validated according to regulatory guidance for assessment of the impact of CHE on key domains of HRQoL. This article provides evidence of strong content and psychometric validity and shows improvements of ≥ 1.3 points in HEIS score and HEIS PDAL score, and improvements of ≥ 1.5 points in HEIS Emb score represent clinically meaningful, important changes. NCT03683719.