Convergent Validity of Suffering and Quality of Life as Measured by The Hidradenitis Suppurativa Quality of Life

BACKGROUND Hidradenitis suppurativa (HS) is a painful chronic, recurrent inflammatory skin disease with great impact on health-related quality of life (HRQOL). Recently, Hidradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC) established HRQOL as a core domain set for HS clinical trials and developed the Hidradenitis Suppurativa Quality of Life (HiSQOL) as a validated outcome measurement instrument. OBJECTIVES To provide further convergent validity of HiSQOL by comparing it to Dermatology Life Quality Index (DLQI) and Pictorial Representation of Illness and Self Measure-Revised 2 (PRISM-R2). METHODS In this cross-sectional study, 103 participants completed HiSQOL, PRISM-R2 and DLQI. PRISM-R2 is an instrument designed to measure suffering and reports the two measures, Illness Perception Measure (IPM) and Self-Illness Separation (SIS). Correlation analyses were performed including a sub-analysis for a subgroup of patients with high scores in the HS-specific domains of HiSQOL. RESULTS A very strong correlation was found between HiSQOL and DLQI (ρ = 0.93, P