A systematic review of 454 randomized controlled trials using the Dermatology Life Quality Index: experience in 69 diseases and 43 countries

Quality of life measurement in assessing treatment effectiveness in urticaria: European experts position statement

In this study, the European Academy of Dermatology and Venereology (EADV) Task Forces on Quality of Life and Patient-Oriented Outcomes and Urticaria and Angioedema has examined the Health-Related Quality of Life (HRQoL) measurement in the treatment of urticaria. The Dermatology Life Quality Index was the most frequently used HRQoL instrument in clinical trials on urticaria. Many reports of clinical trials of urticaria gave no exact numeric results related to HRQoL changes, making clear conclusions and comparisons with other studies impossible. The interpretation of HRQoL impairment data is more difficult when assessed by instruments without severity stratification systems. The minimal clinically significant difference (MCID) is a more clinically oriented and relevant parameter than depending on statistically significant changes in HRQoL scores. Therefore, using HRQoL instruments with established MCID data in clinical trials and clinical practice is preferred.

A Systematic Review of 207 Studies Describing Validation Aspects of the Dermatology Life Quality Index

This study systematically analysed peer-reviewed publications describing validation aspects of the Dermatology Life Quality Index (DLQI) and used Naicker's Critically Appraising for Antiracism Tool to assess risk of racial bias. Seven online databases were searched from 1994 until 2022 for articles containing DLQI validation data. Methodology followed PRISMA guidelines, the protocol was registered in PROSPERO, and articles reviewed independently by two assessors. Of 1,717 screened publications, 207 articles including 58,828 patients from >  49 different countries and 41 diseases met the inclusion criteria. The DLQI demonstrated strong test-retest reliability; 43 studies confirmed good internal consistency. Twelve studies were performed using anchors to assess change responsiveness with effect sizes from small to large, giving confidence that the DLQI responds appropriately to change. Forty-two studies tested known-groups validity, providing confidence in construct and use of the DLQI over many parameters, including disease severity, anxiety, depression, stigma, scarring, well-being, sexual function, disease location and duration. DLQI correlation was demonstrated with 119 Patient Reported Outcomes/Quality of Life measures in 207 studies. Only 15% of studies explicitly recruited minority ethnic participants; 3.9% stratified results by race/ethnicity. This review summarizes knowledge concerning DLQI validation, confirms many strengths of the DLQI and identifies areas for further validation.

Quality of life measurement in urticaria: Position statement of the European Academy of Dermatology and Venereology Task Forces on Quality of Life and Patient-Oriented Outcomes and Urticaria and Angioedema

The European Academy of Dermatology and Venereology (EADV) Task Forces on quality of life (QoL) and patient-oriented outcomes and on urticaria and angioedema recommendations for the assessment of Health-related (HR) QoL in all patients with urticaria in research and practice are as follows: to use the DLQI for adults and the CDLQI for children as dermatology-specific and the CU-Q2oL as a disease-specific HRQoL instruments in urticaria; to use generic instruments to provide comparison of data on urticaria with non-dermatologic diseases, or to compare with healthy volunteers or the general population; to select validated HRQoL instruments with appropriate age limits; to present exact numeric data for HRQoL results; correct title of any HRQoL instrument should be used, along with its correct abbreviation and the reference to its original publication, where possible. The EADV TFs discourage the use of non-validated HRQoL instruments and modified HRQoL instruments that have not undergone standard validation.

The Dermatology Life Quality Index as the primary outcome in randomized clinical trials: a systematic review

BACKGROUND

Primary endpoint measures in clinical trials are typically measures of disease severity, with patient-reported outcome measures (PROMs) relegated as secondary endpoints. However, validation of some PROMs may be more rigorous than that of disease severity measures, which could provide support for a primary role for PROMs.

OBJECTIVES

This study reports on 24 peer reviewed journal articles that used the Dermatology Life Quality Index (DLQI) as primary outcome, derived from a systematic review of randomized controlled trials (RCTs) utlizing DLQI, covering all diseases and interventions.

METHODS

The study protocol was prospectively published on the PROSPERO database, and the study followed PRISMA guidelines. Searches were made using MEDLINE, The Cochrane Library, Embase, Web of Science, Scopus, CINAHL (EBSCO) and PsycINFO databases and records were combined into an Endnote database. Records were filtered for duplicates and selected based on study inclusion/exclusion criteria. Full-text articles were sourced and data were extracted by two reviewers into a bespoke REDCap database, with a third reviewer adjudicating disagreements. The Jadad scoring method was used to determine risk of bias.

RESULTS

Of the 3220 publications retrieved from online searching, 457 articles met the eligibility criteria and included 198 587 patients. DLQI scores were used as primary outcomes in 24 (5.3%) of these studies comprising 15 different diseases and 3436 patients. Most study interventions (17 of 24 studies, 68%) were systemic drugs, with biologics (liraglutide, alefacept, secukinumab, ustekinumab, adalimumab) accounting for 5 of 25 pharmacological interventions (20%). Topical treatments comprised 32% (8 studies), whereas nonpharmacological interventions (n = 8) were 24% of the total interventions (N = 33). Three studies used nontraditional medicines. Eight studies were multicentred (33.3%), with trials conducted in at least 14 different countries, and four studies (16.7%) were conducted in multiple countries. The Jadad risk of bias scale showed that bias was uncertain or low, as 87.5% of studies had Jadad scores of ≥ 3.

CONCLUSIONS

This study provides evidence for use of the DLQI as a primary outcome in clinical trials. Researchers and clinicians can use this data to inform decisions about further use of the DLQI as a primary outcome.

The Dermatology Life Quality Index (DLQI) used as the benchmark in validation of 101 quality-of-life instruments: A systematic review

BACKGROUND

The validation of psychometric measures requires use of other established and standardized validated measures. The Dermatology Life Quality Index (DLQI) is the most widely used tool to measure the burden of skin diseases and assess effectiveness of interventions based on patients' perspective.

OBJECTIVES

The objective of this study was to systematically analyse peer-reviewed publications describing use of the DLQI in validation of other patient-reported outcome (PRO) and quality-of-life (QoL) measures.

METHODS

Seven databases were searched for papers published between January 1994 and December 2022 for articles containing data using DLQI in the validation of other PRO/QoL measures. The methodology followed PRISMA guidelines. The protocol was prospectively registered on PROSPERO.

RESULTS

Of 1717 screened publications, 122 articles including 30,727 patients from 34 different countries with 41 diseases met the inclusion criteria. The DLQI was used in validation of 101 measures: 80 dermatology-specific QoL measures, mostly disease-specific, and 21 generic measures. Of these studies, 47 were cross-cultural adaptations, 116 single arm, 100 were cross-sectional, 18 longitudinal and six randomized placebo controlled. DLQI was used for 14 known group, and correlation for 10 construct, 101 convergent, 10 concurrent, 10 divergent/discriminant and three criterion validity tests using Mann-Whitney (2), Spearman's (80), Pearson's correlation (26) and Student's t-test (1). The DLQI was used in responsiveness analysis in 13 studies.

CONCLUSIONS

This review identified widespread use of the DLQI in validation of other dermatology PRO/QoL measures and confirmed the central role that the DLQI plays as a benchmark in instrument development and validation across dermatology and beyond. The use of the DLQI by so many developers of other instruments has provided a common standard for comparability.

Use of the Dermatology Life Quality Index suite of patient-reported outcome measures in skin-related neglected tropical diseases

Skin-related neglected tropical diseases (NTDs) affect nearly 1 billion people worldwide, contributing to significant physical and psychological morbidity. The DLQI suite of patient-reported outcome measures is widely used to assess the impact of skin diseases on individuals’ health-related quality of life (HRQoL), but it has not been validated for use in skin-related NTDs. The new strategic framework for the control of skin-related NTDs identified the socioeconomic and mental health impact of skin NTDs as research gaps to be addressed. Robust assessments of HRQoL will be an essential part of this research and will require validated appropriate tools, including the DLQI.