A systematic review of the use of the Dermatology Life Quality Index (DLQI) in routine clinical practice: evidence from 287 articles across 56 countries

Although quality of life instruments are widely used in research it is challenging to find evidence of their use in routine clinical use. The most widely used measure for skin disease burden is the Dermatology Life Quality Index (DLQI), and its scores have validated clinical meaning. Although there is a substantial literature confirming the embedding of the DLQI in clinical research and trials, this study aimed to identify evidence of the use of the DLQI in routine clinical practice and explore the nature of its use. The study followed PRISMA guidelines, and the protocol was registered with PROSPERO. Medline (Ovid), Embase, Scopus and CINAHL (EBSCO) databases were systematically searched for articles describing studies using the DLQI in routine clinical practice. Studies were excluded if participants were aged less than 16 years and if there were pre-determined treatment interventions as in a clinical trial. Information was extracted on publications' authors' opinions on the use of the DLQI in their routine practice. A total of 2,718 publications were screened and 287 articles met the inclusion criteria, reporting on 112 diseases and describing 66,434 patients from 56 countries, using the DLQI in at least 29 languages. 124 (42.2%) of the studies were reported as retrospective, 63 (22.0%) were observational, 52 (18.1%) stated DLQI data were retrieved from patient records, 29 (10.1%) as "real life", 39 (13.6%) reported "real world data", and 47 (16.4%) used consecutive patient recruitment. 262 (92.0%) were conducted in a single country, 96 (33.4%) were multicentred studies, 171 (59.6%) were conducted at a single site, 93 (32.4%) were conducted in hospitals, 66 (23.0%) specified outpatient clinics, 38 (13.2%) tertiary care, 4 (1.4%) community, 17 (5.9%) other settings and 35 (12.2%) unspecified. The most common diseases in the study settings were psoriasis (106 studies,36.9%), atopic dermatitis (32,11.1%), urticaria (24,8.4%), hidradenitis suppurativa (22,7.7%), and vitiligo (17, 5.9%). Thirty studies (10.5%) used DLQI score banding. DLQI was widely used in routine care locations internationally, informing clinical decisions and monitoring of treatment. The DLQI was embedded into some clinics' continuing routine practice.