Evaluation of Skindex-16 construct validity in routinely collected psoriasis data: a retrospective analysis of the relationship between overall physician global assessment scores and Skindex-16 and measure discordance.

Patient-reported outcome measures (PROMs) capture disease severity metrics from the patient's perspective, including health-related quality of life (HRQL). Disease-specific validation of PROMs improves their clinical utility. We evaluated construct validity (HRQL) for Skindex-16 in routinely seen psoriasis patients and characterized instances of discordance between Skindex-16 scores and clinician-reported outcome measure of disease severity. We retrospectively studied psoriasis patients seen by University of Utah Dermatology from 2016 to 2020. Cross-sectional construct validity was assessed using quantile regression and Spearman correlation between overall physician global assessment (OPGA) score and Skindex-16 scores. Longitudinal within-subject correlation was performed using linear mixed models. Discordance (10th percentile or lower OPGA and 90th percentile or higher Skindex-16 score [clear skin, poor HRQL; cspHRQL] or the reverse [severe skin, good HRQL; ssgHRQL]) was characterized descriptively. 681 first-visit patients with psoriasis were included. Median overall Skindex-16 score varied by ≥ 10 points across all levels of OPGA scores. OPGA and Skindex-16 domain scores were moderately correlated (emotions ρ = 0.54, functioning ρ = 0.47, and symptoms ρ = 53). Longitudinal correlations were similar (emotion ρxy = 0.54, functioning ρxy = 0.65, symptoms ρxy = 0.47). Visits with cspHRQL discordance occurred for each Skindex-16 domain (emotions = 7, functioning = 13, symptoms = 12). The ssgHRQL group was observed within the emotions (n = 1) and functioning (n = 23) domains. Median Skindex-16 scores are different between different levels of OPGA and show moderate cross-sectional and longitudinal correlation. This supports construct validity in patients with psoriasis. Severe discordance was rare and most often for those with clear skin but poor HRQL. These discordances can prompt further patient-clinician conversation.

Sleep quality and other patient-reported outcomes improve after patients with psoriasis with suboptimal response to other systemic therapies are switched to adalimumab: results from PROGRESS, an open-label Phase IIIB trial.

BACKGROUND: Psoriasis is associated with poor health-related quality of life, including sleep impairment. OBJECTIVE: To assess the extent of sleep impairment, the effect of adalimumab on sleep and other patient-reported outcomes, and correlations between changes in these outcomes and sleep quality in patients with psoriasis. METHODS: Patients in the 16-week, open-label, Phase IIIb PROGRESS trial had chronic plaque psoriasis and suboptimal response to prior therapy (etanercept, methotrexate or narrowband ultraviolet B phototherapy). Adalimumab was self-injected subcutaneously (80 mg at week 0, then 40 mg every other week from week 1). The focus for this analysis was the Medical Outcomes Study Sleep Scale. Other patient-reported outcomes included the Dermatology Life Quality Index (DLQI), Psoriasis Area and Severity Index (PASI), Physician's Global Assessment, a visual analogue scale for psoriasis/psoriatic arthritis (PsA) pain, and the Work Productivity and Activity Index Questionnaire-Specific Health Problems. RESULTS: Patients with psoriasis had impaired sleep at baseline. The degree of sleep impairment was significantly associated with the extent of work productivity for all sleep measures and, for some sleep measures, was associated with DLQI impairment, clinical severity measured by PASI, the presence of PsA, and depression. Adalimumab treatment significantly improved sleep quality by 15% from baseline, as well as DLQI score, pain and work productivity. The improvement in sleep was partially explained (R(2 ) = 0·16, P < 0·001) by improvements in the objectively measured psoriasis signs in PASI. CONCLUSIONS: Adalimumab treatment improved sleep outcomes and other patient-reported outcomes including health-related quality of life, work productivity, daily activity and disease-related pain.