Dermatology Life Quality Index: influence of an illustrated version

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

BACKGROUND

Over 29 years of clinical application, the Dermatology Life Quality Index (DLQI) has remained the most used patient-reported outcome (PRO) in dermatology due to its robustness, simplicity and ease of use.

OBJECTIVES

To generate further evidence of the DLQI's utility in randomized controlled trials (RCTs) and to cover all diseases and interventions.

METHODS

The methodology followed PRISMA guidelines and included seven bibliographical databases, searching articles published from 1 January 1994 until 16 November 2021. Articles were reviewed independently by two assessors, and an adjudicator resolved any opinion differences.

RESULTS

Of 3220 screened publications, 454 articles meeting the eligibility criteria for inclusion, describing research on 198 190 patients, were analysed. DLQI scores were primary endpoints in 24 (5.3%) of studies. Most studies were of psoriasis (54.1%), although 69 different diseases were studied. Most study drugs were systemic (85.1%), with biologics comprising 55.9% of all pharmacological interventions. Topical treatments comprised 17.0% of total pharmacological interventions. Nonpharmacological interventions, mainly laser therapy and ultraviolet radiation treatment, comprised 12.2% of the total number of interventions. The majority of studies (63.7%) were multicentric, with trials conducted in at least 42 different countries; 40.2% were conducted in multiple countries. The minimal clinically importance difference (MCID) was reported in the analysis of 15.0% of studies, but only 1.3% considered full score meaning banding of the DLQI. Forty-seven (10.4%) of the studies investigated statistical correlation of the DLQI with clinical severity assessment or other PRO/quality of life tools; and 61-86% of studies had within-group scores differences greater than the MCID in 'active treatment arms'. The Jadad risk-of-bias scale showed that bias was generally low, as 91.8% of the studies had Jadad scores of ≥ 3; only 0.4% of studies showed a high risk of bias from randomization. Thirteen per cent had a high risk of bias from blinding and 10.1% had a high risk of bias from unknown outcomes of all participants in the studies. In 18.5% of the studies the authors declared that they followed an intention-to-treat protocol; imputation for missing DLQI data was used in 34.4% of studies.

CONCLUSIONS

This systematic review provides a wealth of evidence of the use of the DLQI in clinical trials to inform researchers' and -clinicians' decisions for its further use. Recommendations are also made for improving the reporting of data from future RCTs using the DLQI.

Questionnaire Modifications and Alternative Scoring Methods of the Dermatology Life Quality Index: A Systematic Review

OBJECTIVES

Dermatology Life Quality index (DLQI) is the most widely used health-related quality of life questionnaire in dermatology. Little is known about existing questionnaire or scoring modifications of the DLQI. We aimed to systematically review, identify, and categorize all modified questionnaire versions and scoring methods of the DLQI.

METHODS

We performed a systematic literature search in PubMed, Web of Science, CINAHL, and PsychINFO. Methodologic quality and evidence of psychometric properties were assessed using the Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) and Terwee checklists.

RESULTS

The included 81 articles reported on 77 studies using 59 DLQI modifications. Modifications were used for a combined sample of 25 509 patients with 47 different diagnoses and symptoms from 28 countries. The most frequently studied diseases were psoriasis, hirsutism, acne, alopecia, and bromhidrosis. The modifications were categorized into the following nonmutually exclusive groups: bolt-ons or bolt-offs (48%), disease, symptom, and body part specifications (42%), changes in existing items (34%), scoring modifications (27%), recall period changes (19%), response scale modifications (15%), and illustrations (3%). The evidence concerning the quality of measurement properties was heterogeneous: 4 of 13 studies were rated positive on internal consistency, 1 of 3 on reliability, 3 of 5 on content validity, 9 of 22 on construct validity, 6 of 6 on criterion validity, and 1 of 1 on responsiveness.

CONCLUSION

An exceptionally large number of DLQI modifications have been used that may indicate an unmet need for adequate health-related quality of life instruments in dermatology. The psychometric overview of most questionnaire modifications is currently incomplete, and additional efforts are needed for proper validation.

Patient-reported outcomes assessment tools for use in psoriasis in Spain: A systematic review

OBJECTIVES

To review the literature on validated tools for measuring patient-reported outcomes (PROs) in psoriasis in Spain. To evaluate the psychometric properties of the tools and describe the results of their practical application.

MATERIAL AND METHODS

Systematic review of studies validating or using instruments for assessing PROs in Spanish patients with psoriasis. Literature searches were performed in international (PubMed/Medline) and Spanish (Medes, Ibecs) databases. We also searched databases of instruments for measuring PROs (BiblioPRO, PROQOLID). The review included studies published in English or Spanish up to January 9, 2017. We also checked the reference lists of the key publications identified. The quality of the questionnaires was evaluated based on their psychometric properties (construct, transcultural adaptation, reliability, validity, feasibility, and sensitivity to change).

RESULTS

Eighteen publications were included. Six articles described the validation of Spanish versions of 5 PROs tools: 4 health-related quality of life (HRQoL) questionnaires specific to psoriasis and dermatologic diseases and 1 questionnaire specific to satisfaction with treatment. Our assessment of the HRQoL tools' psychometric properties showed that the PSO-LIFE questionnaire received the highest scores, although specific properties varied from instrument to instrument. The 12 remaining articles were observational studies that used the validated instruments. In use, these tools detected the high impact of psoriasis on HRQoL, especially in young female patients with severe disease.

CONCLUSIONS

We identified 5 specific instruments validated in Spain for scoring PROs in patients with psoriasis. The tools' psychometric properties vary, and it is essential to understand their strengths and weaknesses when selecting the right one for each situation. In use, these questionnaires are able to detect the high impact of psoriasis on patients' HRQoL. PROs provide useful information to complement routine clinical findings in psoriasis and may contribute to improving disease management.

Clinical Goals and Barriers to Effective Psoriasis Care

Engaging global key opinion leaders, the International Psoriasis Council (IPC) held a day-long roundtable discussion with the primary purpose to discuss the treatment goals of psoriasis patients and worldwide barriers to optimal care. Setting clear expectations might ultimately encourage undertreated psoriasis patients to seek care in an era in which great gains in therapeutic efficacy have been achieved. Here, we discuss the option for early treatment of all categories of psoriasis to alleviate disease impact while emphasizing the need for more focused attention for psoriasis patients with mild and moderate forms of this autoimmune disease. In addition, we encourage policy changes to keep pace with the innovative therapies and clinical science and highlight the demand for greater understanding of treatment barriers in resource-poor countries.

The association of socioeconomic and clinical characteristics with health-related quality of life in patients with psoriasis: a cross-sectional study

BACKGROUND

This study aimed to determine the socioeconomic and clinical characteristics affecting health-related quality of life (HRQoL) in patients with psoriasis.

METHODS

A cross-sectional study was conducted between March and June 2015 using data obtained via an Internet-based survey completed by a psoriasis patient group in Korea. The survey included items regarding demographic, socioeconomic, and clinical characteristics and HRQoL. Patients' HRQoL impairment was classified as severe if their Dermatology Life Quality Index Scores were ≥ 11. Factors influencing HRQoL impairment were identified using multivariate logistic regression analysis.

RESULTS

Of the 299 respondents, 161 (53.8%) exhibited severe HRQoL impairment. The Dermatology Life Quality Index scores were significantly associated with gender, annual income, neck psoriasis, psoriasis-related resignation from work, and use of oral and herbal medications. The severity of HRQoL impairment in women was twice that observed in men (odds ratio [OR] = 2.00, 95% confidence interval (CI): 1.05-3.80). Patients with psoriasis on the neck exhibited significantly greater HRQoL impairment than those with psoriasis on other areas of their bodies (OR = 2.30, 95% CI: 1.20-4.43). With respect to the socioeconomic status, patients who earned > 40 million KRW (approximately 34,000 USD; high-income group) showed less HRQoL impairment compared with those who had lower incomes (OR = 0.47, 95% CI: 0.28-0.80). Patients with severe HRQoL impairment used oral (OR = 2.04, 95% CI: 1.20-3.44) and herbal (OR = 1.86, 95% CI: 1.04-3.34) medications more often relative to patients with less severe HRQoL impairment.

CONCLUSIONS

HRQoL in patients with psoriasis was significantly associated with their demographic and socioeconomic characteristics and employment status. The presence of psoriasis on exposed areas of the body was significantly associated with patients' HRQoL and employment status. Further research is required to evaluate the impact of psoriasis on patients' productivity.

Urticaria: impact on quality of life and economic cost

Patients with urticaria suffer itch, swellings, fatigue caused by sleep disturbance and the side effects of medication, and disruption of many facets of their lives. Much progress has been made in formally evaluating the degree of quality-of-life (QoL) impairment suffered by patients with urticaria. This review focuses on QoL in chronic urticaria (>6 weeks duration) and examines QoL measures, including the chronic urticaria-quality of life questionnaire (CU-Q2oL). Patients with urticaria have difficulty identifying and coping with their emotions. The psychiatric comorbidity and the financial burden on the patient and society because of chronic urticaria, is also examined.

Measuring quality of life in patients with psoriasis using the Arabic version for Morocco of the Dermatology Life Quality Index

BACKGROUND

Psoriasis has been demonstrated to have substantial impacts on dermatology-related functional limitations and health-related quality of life (HRQL). This study evaluated the HRQL in Moroccan psoriatics using the Arabic version of the Dermatology Life Quality Index (DLQI) and examined the psychometric properties of the questionnaire.

MATERIALS AND METHODS

The Moroccan Arabic version of the DLQI was developed and approved by the author of the questionnaire. The DLQI was administered to inpatient and outpatient adult psoriatics. Some participants completed the DLQI for a second time. Demographic and clinical characteristics were collected. Reliability of the DLQI was tested using Cronbach's coefficient alpha and intraclass correlation coefficient (ICC). Factor structure was tested by explanatory and confirmatory factor analysis. Construct validity was tested by known-groups comparison using the generalized linear model to assess factors influencing patients' HRQL.

RESULTS

A total of 176 psoriatics completed the questionnaire. The mean age was 36 ± 14 years. The mean Psoriasis Area and Severity Index (PASI) score was 11.8 ± 7.9. The mean DLQI score was 12.7 ± 5.9 (the higher the score the greater the impairment of HRQL). Cronbach's alpha coefficient was 0.84. ICC was 0.97. The principal component analysis confirmed the bidimensional structure of the questionnaire. Factors associated with poorer HRQL were higher PASI (P < 0.001), pustular and erythrodermal clinical forms (P < 0.001), and older age (P = 0.001).

CONCLUSIONS

The Arabic version for Morocco of the DLQI is reliable and valid. Severity of the psoriasis, older age, and severe clinical forms influence the HRQL of patients.

Clinical meaning in skin-specific quality of life instruments: a comparison of the Dermatology Life Quality Index and Skindex banding systems

Clinical meaning can be assigned to scores of health status measures by using a variety of approaches. The anchor-based approach involves determining the difference on a quality of life (QOL) scale that corresponds to a self-reported small but important change on a global scale given concomitantly, which serves as an independent anchor. This article focuses on the anchor-based banding approach and reviews methods to assign clinical meaning to QOL measures, specifically the Dermatology Life Quality Index (DLQI) and Skindex. This article also includes pilot data that compares the DLQI and Skindex using these previously validated banding systems.

The Dermatology Life Quality Index 1994-2007: a comprehensive review of validation data and clinical results

BACKGROUND

The Dermatology Life Quality Index (DLQI) is one of the most widely used dermatology-specific quality of life instruments. Over the last 5 years there has been great interest in its use.

OBJECTIVES

To collect and present all information regarding the technical properties and the clinical use of the DLQI from the date it was published to the end of 2007 for use as a single source of reference.

METHODS

A detailed literature search was conducted using electronic reference databases and the DLQI library in the Department of Dermatology, Cardiff University. All publications mentioning any aspect of the DLQI, from the time of its development to the end of 2007, were identified and the data concerning the DLQI in terms of its psychometric analysis, and use in clinical trials, epidemiological studies and health services research, were extracted and tabulated with all the relevant references.

RESULTS

In total, 272 full articles which have included the DLQI were reviewed. Studies described in these articles were divided into five main categories: psychometric studies, descriptive/epidemiological studies, drug (topical and systemic) trials, clinical practice research, and therapeutic interventions. The DLQI has been used in 33 different skin conditions in 32 countries and is available in 55 languages. Psychometric aspects of the DLQI such as validity, reliability, responsiveness to change, factor structure, and minimal important difference were described in 115 studies. The DLQI has been used in 33 studies assessing the effectiveness of 14 different types of therapeutic interventions and in 37 studies evaluating nine types of clinical practice research. Sixty studies have used it alone or in parallel with other instruments as an outcome measure in clinical trials of 18 systemic drugs while 22 studies have used it in 14 different topical drug trials. The DLQI has also been used in 27 multinational studies.

CONCLUSIONS

During the last 14 years there has been a gradual increase in the international use of the DLQI. The brevity and simplicity of use of the DLQI has resulted in its popularity both in clinical practice and in research. However, there are various issues in particular regarding its unidimensionality, differential item functioning, and minimal clinically important difference, which require further research. This article should facilitate the work of potential users of the DLQI by providing a readily available source of references for different aspects of the DLQI.

Adherence to treatment in patients with psoriasis vulgaris: Turkish experience

BACKGROUND

Treatment adherence has been an important issue in therapies of chronic diseases such as psoriasis vulgaris. There are a few studies on treatment adherence in psoriasis patients in literature.

OBJECTIVE

The goal of this study is to show treatment adherence and the factors that affect it in psoriasis patients in Turkish population.

METHODS

A total of 109 patients with psoriasis vulgaris were enrolled in an 8-week study. A standard questionnaire was completed by the patients. 'Psoriasis Area and Severity Index' and 'Dermatology life quality index' scores and treatment regimens of patients were recorded. At the end of the 8-week therapy, treatment adherence scores were calculated by using self-reported data given by the patients. The level of satisfaction and reasons for missing treatment were recorded.

RESULTS

One hundred three patients (44 men, 59 women) completed the study. The overall rate of treatment adherence was 75%. Single or divorced patients had a significantly higher mean adherence than married ones. There was a significant correlation between adherence and education level. The average level of satisfaction was 44.3%, and the adherence of satisfied patients was statistically more significant than that of the unsatisfied patients. The major two reasons for non-adherence to the therapy were being busy (25.45%) and fed up (21.81%).

CONCLUSION

In the present study, we found that marital status, education and satisfaction level were important for treatment adherence. We suggest that further studies with different contributing factors consisting of social, cultural and psychological effects may be useful for treatment adherence in psoriasis patients.

The Practical Reality of Using a Patient-Reported Outcome Measure in a Routine Dermatology Clinic

OBJECTIVE

To explore whether clinicians used formal quality of life (QoL) information if provided by patients completing the Dermatology Life Quality Index (DLQI) questionnaire and whether the information influenced treatment decision-taking.

METHODS

The DLQI was completed by adult patients attending a dermatology secondary-care clinic as they arrived at their appointment and given to the clinician. Clinicians recorded whether the DLQI information was used and whether it influenced treatment decision-making.

RESULTS

A total of 417 patients attended and 268 questionnaires (64.3%) were completed. The mean DLQI score was 7 (median = 5, range = 0-30). In 64 consultations (28.8%), clinicians used the DLQI information; in 37 of these consultations (57.8%) the DLQI information influenced the clinicians' treatment decision-making. The mean DLQI score for these 37 consultations was 11.3 (median = 10.0, range = 0-29), indicating a large effect on patients' QoL. QoL discussion occurred in 85 of 98 consultations observed. The domains of QoL most frequently discussed concerned symptoms (74 consultations) and problems caused by the treatment (24 consultations).

CONCLUSIONS

Clinicians may use formal QoL information if available in routine clinics. Treatment decisions may be influenced for those with high QoL impairment. Routine systematic assessment of QoL may therefore be of benefit.

Use of the Dermatology Life Quality Index in filarial lymphoedema patients

The global programme to eliminate lymphatic filariasis has alleviation of suffering and disability as one of its components, and many efforts are being taken across the globe in this direction. However, there is no effective tool to assess the impact of these efforts on patients' quality of life and/or lessening of disability and suffering. The present paper reports the use of the Dermatology Life Quality Index (DLQI) in filarial lymphoedema patients. DLQI scores were collected from 203 patients recruited from a clinic and from the community. The DLQI score ranged from 0 to 17, and a mean score of 2.7 (SD 4.4) or 9.0% disability. This score is lower than many skin diseases reported so far. The scores for individual questions vary, but the degree of consistency of responses between questions is high. The differences between sexes, place of recruitment and grades of lymphoedema are not significant. Although the DLQI measures the quality of life due to lymphoedema, this study further warrants development of a good quality-of-life index for lymphoedema patients.

Does enough quality of life-related discussion occur during dermatology outpatient consultations?

BACKGROUND

Dermatologists' assessments of how their patients' lives are affected by the skin disease are of importance for informing clinical decisions. However, there is no information about how often quality of life (QoL) issues are discussed in outpatient consultations.

OBJECTIVE

To examine the relationship between the extent of QoL-related discussion during dermatology outpatient consultations, and the current impact of the disease on patients' lives.

PATIENTS AND METHODS

A total of 238 consultations were observed in a teaching dermatology outpatient department for QoL-related discussion initiated by either the clinician or the patient. Following the consultation, all patients were posted a Dermatology Life Quality Index (DLQI) questionnaire to complete and return within 1 week.

RESULTS

QoL discussion was absent in 40% of consultations. Consultants initiated the fewest QoL discussions with patients, and nurses the most (P < 0.0001). One hundred and twenty-eight (54%) patients returned the DLQI, 114 (48%) of which were evaluable. The mean score was 5.6, SD +/- 6.6, median 3, range 0-29. The mean DLQI score for the patients with whom there was no QoL discussion was 4.0 +/- 4.7, n = 55, compared with the mean DLQI score for patients with whom QoL was discussed 6.8 +/- 7.2, n = 59 (P < 0.001).

CONCLUSION

This study demonstrates that little information concerning QoL is elicited during dermatology outpatient consultations.

A critical review of Quality-of-Life Scales for Psoriasis

Psoriasis can have a major impact on the lives of patients who have psoriasis and many different methods are described to measure this effect. This article describes four general health measures, six dermatology-specific measures, four psoriasis-specific measures, and four utility measure concepts that are used in psoriasis. For each of these, the extent of validation, including reliability of each measure and correlation with other measures, is described. The experience of use of each measure is summarized and key references listed. Advice is given concerning strategy for choosing which measures to use.

Translating the Science of Quality of Life into Practice: What Do Dermatology Life Quality Index Scores Mean?

This study's aim was to determine the relationship between Dermatology Life Quality Index (DLQI) scores and a Global Question (GQ) concerning patients' views of the overall impairment of their skin-related quality of life (QoL), and to express this relationship by identifying bands of DLQI scores equivalent to each GQ descriptor. A DLQI questionnaire and the GQ were mailed to 3834 adult general dermatology outpatients. There were 1993 (52%) responses: male 841; female 1152. Mean DLQI score = 4.86 (range 0-30, standard deviation (SD) = 5.83). Mean GQ score = 1.22 (range 0-4, SD = 1.20). The mean, mode, and median of the GQ scores for each DLQI score were used to devise several sets of bands of DLQI scores, and kappa coefficients of agreement calculated. The set proposed for adoption is: DLQI scores 0-1 = no effect on patient's life (GQ = 0, n = 754); DLQI scores 2-5 = small effect on patient's life (GQ = 1, n = 611); DLQI scores 6-10 = moderate effect on patient's life (GQ = 2, n = 327); DLQI scores 11-20 = very large effect on patient's life (GQ = 3, n = 242); DLQI scores 21-30 = extremely large effect on patient's life (GQ = 4, n = 59); kappa coefficient 0.489. Banding of the DLQI will aid the clinical interpretation of an individual's DLQI score and allow DLQI scores to inform clinical decisions.