Evidence map›Paper›PMID 41735734›Full record

ArticleJournal of patient-reported outcomes2026

Confirmation of unidimensionality of the Dermatology Life Quality Index (DLQI) using a multinational 3,408 patient dataset.

Jeffrey Johns, Sam Salek, Faraz Ali, Florence Dalgard, Jörg Kupfer, Andrew Y Finlay

Abstract readMulticenter Study
In one paragraph

Article in Journal of patient-reported outcomes, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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5 · Who and what money

Authors and funding

6 authors.

Jeffrey JohnsDivision of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK. johnsj4@cardiff.ac.uk.ORCID http://orcid.org/0000-0002-1628-4306
Sam SalekSchool of Health, Medicine and Life Science, University of Hertfordshire, Hatfield, AL10 9AB, UK.
Faraz AliDivision of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK.
Florence DalgardNational Center for Dual Diagnosis, Innlandet Hospital Trust, Brumundal, Norway.
Jörg KupferInstitute of Medical Psychology, Justus Liebig University, Giessen, Germany.
Andrew Y FinlayDivision of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe Dermatology Life Quality Index (DLQI) was designed to be a simple, practical questionnaire for routine clinical use and is the most widely used tool to measure the burden of skin diseases and assess effectiveness of interventions based on patients’ perspective. The aim of this study was to further validate the DLQI using a multinational European study dataset.

methodsData from a cross-sectional study conducted in 13 European countries were analysed. In each dermatology clinic, 250 consecutive adult out-patients were recruited. A wide range of classical test theory and IRT tools were used to investigate unidimensionality and known-group properties.

resultsFrom 3,635 patients, 3408 completed the DLQI with no missing data. 55.8% of patients were female, mean age 46.6 years (SD = 17.82). The commonest conditions were psoriasis (17.4%), non-melanoma skin cancer (10.8%), infection of the skin (6.7%), hand eczema (6.2%) and acne (6.2%). Using DLQI score banding, the patients’ disease had no effect (n = 962, 28.2%), small (912, 26.8%), moderate (674, 19.8%), very large (691, 20.3%) or extremely large effect (169, 5.0%) on their quality of life. Psychometric analyses employing eigenvalues, scree plots, item-response theory (IRT) and very simple structure indicated unidimensionality. Cumulative explained common variance did not significantly increase from 0.618 with additional factors. Confirmatory factor analysis fits for a 1-factor solution were very good and a 1-factor model was optimum. IRT indicated good fit statistics, no misfitting items (infit and outfit), and no local dependencies (LG2 and Q3). Cronbach’s alpha was 0.90. Cohen’s-d effect sizes for DLQI scores between different EQ-5D item levels were moderate (> 0.5) or large (> 0.8), and large between different disease severity levels. Good correlation was found between EQ-5D VAS scale and DLQI score (r2 =-0.409, p < 0.001). Known group analysis of DLQI score by severity was significant between groups (p < 0.001).

conclusionAnalysis showed good psychometric properties confirming a 1-factor unidimensional model.

Indexed as

Quality of LifeSkin DiseasesAdultAgedCross-Sectional StudiesEuropeFemaleHumansMaleMiddle AgedPsychometricsReproducibility of ResultsSurveys and QuestionnairesDermatology Life Quality IndexDLQIItem response theoryUnidimensionalityValidation

Identifiers

PMID41735734
PMCPMC13038833

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