Application of the Dermatology Life Quality Index in Clinical Trials of Biologics for Psoriasis

The significance of patient-reported outcomes (PROs) is increasingly being acknowledged and quality of life (QOL) has become an integral element of the assessment of overall burden of disease. Psoriasis has been known for its major impact on patients' QOL and various generic, dermatology-specific and psoriasis-specific self-administered psychometric instruments have been used over the years to assess the QOL of psoriasis patients. However, the Dermatology Life Quality Index (DLQI) is the most widely used QOL measure among these measures in psoriasis-related clinical trials. A number of topical and systemic treatments have been used in the management of psoriasis and lately biologics have emerged as a new and promising treatment modality for difficult-to-treat psoriasis. The evidence on the efficacy of these agents has been growing dramatically with QOL being used as one of the primary outcome measures in many clinical trials. The aim of this paper is to give an overview of the use of the DLQI as an outcome measure for assessing the QOL impact of biologics on psoriasis patients. Furthermore, the efficacy of five commonly used biologics has been compared in terms of their ability to improve the QOL assessed by the DLQI. This review has revealed that there is a variation in the efficacy of various biologics in terms of QOL improvement with the mean reduction in the DLQI scores being highest for ustekinumab 90 mg (mean DLQI score reduction=9.5), followed by infliximab (8.5), etanercept 50 mg, twice a week (7.7), adalimumab (6.3), and alefacept (4.0).