Utility of the Dermatology Life Quality Index at initiation or switching of biologics in real-life Japanese patients with plaque psoriasis: Results from the ProLOGUE study.

Background: Plaque psoriasis significantly affects patients' health-related quality of life. To aid treatment decisions, not only objective assessment by physicians but also subjective assessment by patients is important.

Objective: To assess the significance of Dermatology Life Quality Index (DLQI) evaluation at the time of biologics introduction in clinical practice in Japanese patients with plaque psoriasis.

Methods: This was a single-arm, open-label, multicenter study. At baseline, Psoriasis Area and Severity Index (PASI) and DLQI scores were measured and stratified based on DLQI scores ≥6/≤5 and PASI scores ≤10/>10. Other patient-reported outcomes assessed included EQ-5D-5L, itch numerical rating scale (NRS), skin pain NRS, Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-8 (PHQ-8), Sleep Problem Index-II (SPI-II), and Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9).

Results: Of the 73 enrolled patients, 23 had PASI scores ≤10. Those with PASI/DLQI scores >10/≥6 had a significantly higher median PASI score than those with PASI/DLQI scores >10/≤5 (p = 0.0125). Regardless of PASI scores (>10/≤10), median itch NRS and GAD-7 scores were significantly higher in patients with DLQI scores ≥6 than in those with DLQI scores ≤5 (itch NRS, p = 0.0361 and p = 0.0086, respectively; GAD-7, p = 0.0167 and p = 0.0273, respectively). Patients with PASI/DLQI scores ≤10/≥6 had significantly higher skin pain NRS (p = 0.0292) and PHQ-8 (p = 0.0255) scores and significantly lower median SPI-II scores (p = 0.0137) and TSQM-9 Effectiveness domain scores (p = 0.0178) than those with PASI/DLQI scores ≤10/≤5.

Conclusions: DLQI may be useful for assessing patients' concerns that cannot be identified by PASI alone while initiating biologics or switching from other biologics in clinical practice.