Testing the Psychometric Properties of 9 Bolt-Ons for the EQ-5D-5L in a General Population Sample.

OBJECTIVES: We aimed to assess the psychometric performance and added value of 9 existing bolt-ons (breathing problems, cognition, hearing, self-confidence, skin irritation, sleep, social relationships, tiredness, and vision) for the EQ-5D-5L in a general population sample. METHODS: The EQ-5D-5L, 9 bolt-ons, SF-6Dv1, Patient-Reported Outcomes Measurement Information System (PROMIS)-29+2, PROMIS Global Health, and Satisfaction with Life Scale were completed in an online cross-sectional survey among a general adult population sample in Hungary (n = 1587). The following psychometric properties were tested for the EQ-5D-5L + bolt-on(s): ceiling, divergent and convergent validity, structural validity, known-group validity, and explanatory power. RESULTS: Adding sleep (30%), tiredness (24%), or vision (21%) substantially reduced the ceiling of the EQ-5D-5L (41%). Cognition, sleep, social relationships, and tiredness correlated with corresponding PROMIS and SF-6D items (rs = ǀ0.32ǀ - ǀ0.73ǀ). All bolt-ons, except cognition and self-confidence, loaded on a different factor from the EQ-5D-5L dimensions. Breathing, hearing, skin irritation, and vision significantly improved known-group validity in relevant health condition groups. The sleep bolt-on improved known-group validity in 9 of 13 chronic health conditions. Tiredness had the largest impact on explaining EQ VAS score variance in 8 of 13 conditions. Hearing and vision improved the ability of the EQ-5D-5L to capture declining health with age, whereas self-confidence and social relationships were valuable for mental health assessment. CONCLUSIONS: This study established the validity of multiple bolt-ons for the EQ-5D-5L and highlights the usefulness of including relevant bolt-ons in population-based and patient surveys. Our findings inform the further development of these bolt-ons and the bolt-on item selection for clinical studies.

Subjective Well-Being Population Norms and Inequalities in Hungary: A Large Cross-Sectional, Internet-Based Survey.

OBJECTIVES: This study aimed to provide subjective well-being (SWB) population norms in Hungary and explore the contribution of explanatory factors of SWB inequality among the Hungarian adult general population. METHODS: The data originated from a large representative internet-based cross-sectional survey in Hungary, which was conducted in 2020. We applied validated multi-item instruments for measuring SWB, namely Satisfaction With Life Scale (SWLS) and World Health Organization-Five Well-Being Index (WHO-5). Multiple linear regressions were used to examine the relationship between demographic-socioeconomic-health status and both well-being instruments. The concentration index (CI) was used to measure the degree of income-related inequality in well-being. RESULTS: A total of 2001 respondents were enrolled with the means ± SD WHO-5 scores and SWLS scores of 0.51 ± 0.21 and 0.51 ± 0.23, respectively. Higher household income, higher educational level, better general health status, and absence of chronic morbidity were significant positive predictors for both WHO-5 and SWLS scores. The CI of WHO-5 scores was lower than that of SWLS scores in the total sample (0.0480 vs 0.0861) and in subgroups by gender (male, 0.0584 vs 0.1035; female, 0.0302 vs 0.0726). The positive CI values implied a slight pro-rich SWB inequality in this population. The regression analyses showed a positive association of SWB with having a higher household income and a better general health status. CONCLUSIONS: This is the first representative study in Hungary to compare population norm of 2 well-being instruments and analyze well-being inequality. Slight pro-rich inequality was found consistently with both SWB measures. Our findings support the need for health and social policies that effectively tackle inequalities in Hungary.

Validity, test-retest reliability, and responsiveness of the Indonesian version of FACIT-COST measure for subjective financial toxicity.

BACKGROUND: Financial toxicity describes the impairment of financial wellbeing in patients due to the burden of cancer diagnosis and care. The COST: A Functional Assessment of Chronic Illness Therapy Measure of Financial Toxicity (FACIT-COST) is the most widely used cancer-specific measure of subjective financial toxicity, having been validated in multiple languages, but not in Indonesian. This study aimed to validate the Indonesian version of FACIT-COST in a breast cancer sample. METHODS: A single-center prospective cohort study was performed in Indonesia. Female breast cancer patients aged ≥ 18 undergoing treatment at baseline were invited to participate and followed for up to six months. The survey included the official Indonesian version of FACIT-COST (v2) which was administered to the patients by interviewers. Clinical information (e.g., metastasis status, disease duration) was provided based on medical records. The following measurement properties of FACIT-COST were tested: distributional characteristics, structural validity (principal component [PCA] and confirmatory factor analyses [CFA]), internal consistency reliability (Cronbach's alpha and McDonald's omega), known-groups validity (Mann-Whitney U or Kruskal-Wallis H test), test-retest reliability, and responsiveness to change. RESULTS: Overall, 300 female patients participated at baseline. No patients reported the best or worst possible FACIT-COST total scores. The PCA proposed a two-factor model structure for the instrument, which was confirmed by the CFA (RMSEA = 0.042, SRMR = 0.049, CFI = 0.99, TLI = 0.99). The internal consistency reliability of the two factors was considered adequate (Cronbach's alpha = 0.774-0.882, McDonald's omega = 0.786-0.888). The FACIT-COST total score significantly discriminated across the following known-groups: age, education, residential setting, income, employment, metastasis status, number of symptoms, and financial coping strategies. The FACIT-COST demonstrated excellent test-retest reliability (intraclass correlation coefficient = 0.96) and satisfactory responsiveness to change (standardized response mean and effect size ranges=|0.39| to |0.92|). CONCLUSIONS: This is the first study to validate the FACIT-COST in patients with breast cancer and to present the measurement properties of the Indonesian version of FACIT-COST. The Indonesian FACIT-COST demonstrates acceptable psychometric performance and shows potential as a valid measure of subjective financial toxicity. The instrument may serve as a valuable tool for informing health policies that focus on providing resource support to improve cancer care in Indonesia.

The EQ-5D-5L valuation study for Trinidad and Tobago.

PURPOSE: The 2016 EQ-5D-3L value set for Trinidad and Tobago (T&T) allows for the calculation of EQ-5D-5L values via the crosswalk algorithm. The 2016 value set was based on methods predating the EQ-VT protocol, now considered the gold standard for developing EQ-5D value sets. Furthermore, direct elicitation of EQ-5D-5L is preferred over crosswalked values. This study aimed to produce an EQ-5D-5L value set for T&T. METHODS: A representative sample (age, sex, geography) of adults each completed 10 composite Time Trade-Off (cTTO) tasks and 12 Discrete Choice Experiment (DCE) tasks in face-to-face interviews. The cTTO data were analyzed using a Tobit model that corrects for heteroskedasticity. DCE data were analyzed using a mixed logit model. The cTTO and DCE data were combined in hybrid models. RESULTS: One thousand and seventy-nine adults completed the valuation interviews. Among the modelling approaches that were explored, the hybrid heteroskedastic Tobit model produced all internally consistent, statistically significant coefficients, and performed best in terms of out-of-sample predictivity for single states. Compared to the existing EQ-5D-5L crosswalk set, the new value set had a higher number of negative values (236 or 7.6% versus 21 or 0.7%). The mean absolute difference was 0.157 and the correlation coefficient between the two sets was 0.879. CONCLUSION: This study provides a value set for the EQ-5D-5L for T&T using the EQ-VT protocol. We recommend this value set for QALY computations relating to T&T.

Time perspective profile and self-reported health on the EQ-5D.

OBJECTIVES: Time perspective (TP) is a psychological construct that is associated with several health-related behaviours, including healthy eating, smoking and adherence to medications. In this study, we aimed to examine the associations of TP profile with self-reported health on the EQ-5D-5L and to detect which domains display response heterogeneity (cut-point shift) for TP. METHODS: We conducted a secondary analysis of EQ-5D-5L data from a representative general population sample in Hungary (n = 996). The 17-item Zimbardo Time Perspective Inventory was used to measure individuals' TP on five subscales: past-negative, past-positive, present-fatalist, present-hedonist and future. The associations between TP subscales and EQ-5D-5L domain scores, EQ VAS and EQ-5D-5L index values were analysed by using partial proportional odds models and multivariate linear regressions. RESULTS: Respondents that scored higher on the past-negative and present-fatalist and lower on the present-hedonist and future subscales were more likely to report more health problems in at least one EQ-5D-5L domain (p < 0.05). Adjusting for socio-economic and health status, three EQ-5D-5L domains exhibited significant associations with various TP subscales (usual activities: present-fatalist and future, pain/discomfort: past-negative and future, anxiety/depression: past-negative, present-fatalist, present-hedonist and future). The anxiety/depression domain showed evidence of cut-point shift. CONCLUSIONS: This study identified response heterogeneity stemming from psychological characteristics in self-reported health on the EQ-5D-5L. TP seems to play a double role in self-reported health, firstly as affecting underlying health and secondly as a factor influencing one's response behavior. These findings increase our understanding of the non-health-related factors that affect self-reported health on standardized health status measures.

Hungarian population norms for the 15D generic preference-accompanied health status measure.

OBJECTIVES: 15D is a generic preference-accompanied health status measure covering a wide range of health areas, including sensory functions. The aim of this study was to establish population norms for the 15D instrument in Hungary. METHODS: 2000 members of the Hungarian adult general population participated in an online cross-sectional survey in August 2021. The sample was broadly representative in terms of gender, age groups, highest level of education, geographical region, and settlement type. Index values were derived using the Norwegian 15D value set. In addition to providing population norms, mean index values were computed for 32 physical and 24 mental health condition groups. RESULTS: Most respondents (78.7%) reported problems in at least one 15D domain. The most problems were reported with sleeping (50.7%), followed by vitality (49.2%), distress (43.6%), discomfort and symptoms (31.2%), depression (31.1%), sexual activities (29.6%), breathing (28.1%), and vision (27.8%). The mean 15D index value was 0.810. With advancing age categories, the 15D index values showed an inverse U-shaped curve. Generally, mean index values in respondents with mental health conditions were lower [range 0.299 (post-traumatic stress disorder) to 0.757 (smoking addiction)] than those of respondents with physical conditions [range 0.557 (liver cirrhosis) to 0.764 (allergies)]. CONCLUSIONS: This study provided 15D population norms of the Hungarian general population; furthermore, this is the first study to provide population norms for the 15D in any country. The values established in this study can serve as benchmarks for evaluating efficacy outcomes in clinical trials, quantifying disease burden and identifying unmet needs.

Content validity of the EQ-5D-5L with skin irritation and self-confidence bolt-ons in patients with atopic dermatitis: a qualitative think-aloud study.

OBJECTIVES: Two bolt-on dimensions (skin irritation, self-confidence) have been developed for the EQ-5D-5L to improve its content validity and responsiveness in psoriasis. However, the two bolt-ons are not strictly psoriasis-specific and are potentially relevant in other skin conditions. This study aims to explore the content validity of the EQ-5D-5L with two bolt-ons in patients with atopic dermatitis (AD). METHODS: In 2021-2022, qualitative, semi-structured interviews were conducted with 20 adult AD patients at a university dermatology clinic in Hungary. We aimed for a heterogeneous sample in terms of age, gender, education and disease severity. Patients completed the EQ-5D-5L with two bolt-ons using a think-aloud protocol. Probing questions were posed to investigate item relevance, potential conceptual overlaps, missing concepts and the appropriateness of the recall period. Interview transcripts were subjected to thematic analysis. RESULTS: The EQ-5D-5L with the two bolt-ons covered the most important aspects of health-related quality of life in AD patients. Most patients found both the skin irritation and self-confidence bolt-ons relevant. Fifteen potential missing concepts were identified, but only two (social relationships, judgement by others) were identified by more than one patient. A smaller conceptual overlap was found between the skin irritation and pain/discomfort dimensions in 7 patients (35%). Half the patients expressed a preference for a recall period of 1 week rather than of 'today'. CONCLUSIONS: The EQ-5D-5L with skin irritation and self-confidence bolt-ons showed good relevance, comprehensiveness and comprehensibility in patients with AD. However, in terms of comprehensiveness, social relationships and judgement by others (stigma) may be missing from the questionnaire.

Comprehensive Score for Financial Toxicity and Health-Related Quality of Life in Patients With Cancer and Survivors: A Systematic Review and Meta-Analysis.

OBJECTIVES: Financial toxicity is recognized as an important adverse effect of cancer treatment that may decrease patients' health-related quality of life (HRQOL). We aim to perform a systematic review and meta-analysis on studies investigating the association of HRQOL and financial toxicity measured with the Comprehensive Score for Financial Toxicity in patients with cancer and survivors. METHODS: A systematic literature search was completed in PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature, and PsycInfo (last update April 2022). Methodological quality of included studies was assessed using the Appraisal Tool for Cross-Sectional Studies and the Critical Appraisal Skills Program Cohort Study Checklist. Where possible, study outcomes were pooled by random-effects meta-analysis. RESULTS: Thirty-one studies were included with a combined sample of 13 481 patients and survivors with more than 25 cancer types from 9 countries. Nineteen different validated HRQOL instruments were used in these studies, with the Functional Assessment of Cancer Therapy - General (n = 9), the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (n = 5), and EQ-5D (n = 5) being the most common. All but one included studies reported that higher financial toxicity was significantly associated with worse HRQOL. Ten HRQOL domains were correlated with financial toxicity, including physical health (r = 0.34-0.66), social health (r = 0.16-0.55), mental health (r = 0.21-0.54), and daily functioning (r = 0.23-0.52). The meta-analysis indicated a moderate correlation between financial toxicity and overall HRQOL as measured by the Functional Assessment of Cancer Therapy instruments (r = 0.49, 95% confidence interval 0.44-0.54). CONCLUSIONS: This is the first systematic review and meta-analysis to summarize the literature on the association of financial toxicity and HRQOL in patients with cancer and survivors. Our findings substantiate financial toxicity as a relevant outcome of cancer care that is associated with a decline of HRQOL.

A Direct Comparison of the Measurement Properties of EQ-5D-5L, PROMIS-29+2 and PROMIS Global Health Instruments and EQ-5D-5L and PROPr Utilities in a General Population Sample.

OBJECTIVES: We aimed to compare measurement properties of the 5-level version of EQ-5D (EQ-5D-5L) and 2 Patient-Reported Outcomes Measurement Information System (PROMIS) short forms, PROMIS-29+2 and PROMIS Global Health (PROMIS-GH-10), and of EQ-5D-5L and PROMIS-preference scoring system (PROPr) utilities. METHODS: A cross-sectional survey was conducted in a general population sample in Hungary (N = 1631). We compared the following measurement properties at the level of items, domains, and utilities, the latter using corresponding US value sets: ceiling and floor, informativity (Shannon's indices), agreement, convergent, and known-group validity. For the analyses, PROMIS items/domains were matched to EQ-5D-5L domains that cover similar concepts of health. RESULTS: The majority of PROMIS items showed enhanced distributional characteristics, including lower ceilings and higher informativity than the EQ-5D-5L. Good convergent validity was established between EQ-5D-5L and PROMIS domains capturing similar aspects of health. Mean EQ-5D-5L utilities were substantially higher than those of PROPr (0.864 vs 0.535). EQ-5D-5L utilities correlated moderately or strongly with PROPr (r = 0.61), PROMIS-GH-10 physical (r = 0.68), and mental health summary scores (r = 0.53). EQ-5D-5L utilities decreased with age, whereas PROPr utilities slightly increased with age. EQ-5D-5L utilities discriminated significantly better in 12/28 (ratio of F-statistics) and 18/26 (area under the receiver-operating characteristics curve ratio) known groups defined by age, self-perceived health status, and self-reported physician-diagnosed health conditions, including hypertension, diabetes, coronary heart disease, chronic kidney disease, and stroke. CONCLUSIONS: This study provides comparative evidence on the measurement properties of EQ-5D-5L, PROMIS-29+2, and PROMIS-GH-10 and informs decisions about the choice of instruments in population health surveys for assessment of patients' health and for cost-utility analyses.

A head-to-head comparison of the EQ-5D-5L and 15D descriptive systems and index values in a general population sample.

BACKGROUND: The EQ-5D-5L and 15D are generic preference-accompanied health status measures with similar dimensions. In this study, we aim to compare the measurement properties of the EQ-5D-5L and 15D descriptive systems and index values in a general population sample. METHODS: In August 2021, an online cross-sectional survey was conducted in a representative adult general population sample (n = 1887). The EQ-5D-5L and 15D descriptive systems and index values were compared in terms of ceiling and floor, informativity (Shannon's Evenness index), agreement, convergent and known-groups validity for 41 chronic physical and mental health conditions. Danish value sets were used to compute index values for both instruments. As a sensitivity analysis, index values were also estimated using the Hungarian EQ-5D-5L and Norwegian 15D value sets. RESULTS: Overall, 270 (8.6%) and 1030 (3.4*10-6%) unique profiles occurred on the EQ-5D-5L and 15D. The EQ-5D-5L dimensions (0.51-0.70) demonstrated better informativity than those of 15D (0.44-0.69). EQ-5D-5L and 15D dimensions capturing similar areas of health showed moderate or strong correlations (0.558-0.690). The vision, hearing, eating, speech, excretion and mental function 15D dimensions demonstrated very weak or weak correlations with all EQ-5D-5L dimensions, which may indicate potential room for EQ-5D-5L bolt-ons. The 15D index values showed lower ceiling than the EQ-5D-5L (21% vs. 36%). The mean index values were 0.86 for the Danish EQ-5D-5L, 0.87 for the Hungarian EQ-5D-5L, 0.91 for the Danish 15D and 0.81 for the Norwegian 15D. Strong correlations were found between the index values (Danish EQ-5D-5L vs. Danish 15D 0.671, Hungarian EQ-5D-5L vs. Norwegian 15D 0.638). Both instruments were able to discriminate between all chronic condition groups with moderate or large effect sizes (Danish EQ-5D-5L 0.688-3.810, Hungarian EQ-5D-5L 1.233-4.360, Danish 15D 0.623-3.018 and Norwegian 15D 1.064-3.816). Compared to the 15D, effect sizes were larger for the EQ-5D-5L in 88-93% of chronic condition groups. CONCLUSIONS: This is the first study to compare the measurement properties of the EQ-5D-5L and 15D in a general population sample. Despite having 10 fewer dimensions, the EQ-5D-5L performed better than the 15D in many aspects. Our findings help to understand the differences between generic preference-accompanied measures and support resource allocation decisions.

Hungarian PROMIS-29+2: psychometric properties and population reference values.

OBJECTIVES: This study aims to assess psychometric properties of the Hungarian PROMIS-29+2 profile measure and provide general population reference values for Hungary. METHODS: An adult general population sample (n = 1700) completed PROMIS-29+2 v2.1 in an online survey. The following psychometric properties were assessed: floor and ceiling effect, convergent validity with SF-36v1 domains, internal consistency (McDonald's omega), unidimensionality, local independence, monotonicity, graded response model (GRM) fit and differential item functioning (DIF). Age- and gender-specific reference values were established using the US item calibrations. RESULTS: Depending on scale orientation, high floor or ceiling effects were observed for all domains (25.2-60.7%) except for sleep disturbance. McDonald's omega for domains ranged from 0.87-0.97. Unidimensionality, local independence and monotonicity were supported and the GRM adequately fitted for all but one domains. The sleep disturbance domain demonstrated item misfit, response level disordering and low discrimination ability, particularly for item Sleep116 ('refreshing sleep'). Strong correlations were observed between PROMIS-29+2 and corresponding SF-36 domains (rs=│0.60│ to │0.78│). No DIF was detected for most sociodemographic characteristics. Problems with physical function, pain interference and social roles tended to increase, whereas problems with anxiety, depression, fatigue and cognitive function declined with age (p < 0.01). In all domains except for cognitive function, more health problems occurred in females than in males (p < 0.001). CONCLUSION: The Hungarian PROMIS-29+2 shows satisfactory psychometric properties; however, the sleep disturbance domain substantially underperforms that requires further attention. Population reference values were generated that facilitate the interpretation of health outcomes in various patient populations.

Health utilities and willingness to pay in adult patients with coeliac disease in Hungary.

BACKGROUND: Coeliac disease (CD) is a life-long food-related disorder with a global prevalence of approximately 1%. Patients with CD often experience reduced health-related quality of life that could improve with a strict adherence to a gluten-free diet (GFD). OBJECTIVES: To obtain visual analogue scale (VAS), time trade-off (TTO) and willingness-to-pay (WTP) values amongst patients with CD. METHODS: In 2020-2021, a cross-sectional online survey was conducted amongst 312 adult CD patients in Hungary. Patients completed the Gastrointestinal Symptom Rating Scale (GSRS) and evaluated their current health and three hypothetical health state vignettes defined based on dietary adherence using VAS, conventional 10-year TTO and WTP. Multivariate regressions were used to explore the effect of patients' demographic and clinical characteristics on utility and WTP values. RESULTS: Mean VAS values for current health and 'CD with strict adherence to GFD', 'CD with loose adherence to GFD' and 'CD without GFD' hypothetical health states were 79.69 ± 18.52, 85.36 ± 16.18, 62.44 ± 19.91 and 36.69 ± 25.83, respectively. Corresponding mean TTO utilities were: 0.90 ± 0.19, 0.91 ± 0.20, 0.87 ± 0.23 and 0.76 ± 0.29. Mean annual WTP values for returning to full health were: €845 ± 1077, €648 ± 1002, €862 ± 1135 and €1251 ± 1496. Older age at diagnosis, male sex, more severe gastrointestinal symptoms (GSRS) and having comorbidities were associated with lower VAS and TTO or higher WTP values for current own health (p < 0.05). CONCLUSION: This is the first study to report TTO utilities for CD health states. Strict adherence to the GFD may result in substantial health gains in symptomatic patients. Utilities and WTP results can be used to estimate benefits of GFD in cost-utility and cost-benefit analyses.

Societal costs and health related quality of life in adult atopic dermatitis.

BACKGROUND: Cost-of-illness studies are widely used for healthcare decision-making in chronic conditions. Our aim was to assess the cost-of-illness of adult atopic dermatitis (AD) from the societal perspective in Hungary. METHODS: We conducted a multicentre, cross-sectional questionnaire survey between February 2018 and January 2021. Data was collected from consecutive AD patients aged ≥ 18 years and their physicians at dermatology departments in Hungary. We calculated direct and indirect costs, including costs for treatments, outpatient visits, hospital admissions, informal care, travel costs and productivity loss. To assess indirect costs, the Work Productivity and Activity Impairment (WPAI) questionnaire was used to collect data, and costs were estimated with the human capital approach. Generalized linear model was used to analyse predictors of total, direct and indirect costs. RESULTS: Altogether 218 patients completed the survey (57.8% female) with an average age of 31.3 (SD = 11.7). Patients' average Dermatology Life Quality Index (DLQI) score was 13.5 (SD = 8.5). According to Eczema Area and Severity Index (EASI) score, 2.3% (n = 5), 21.2% (n = 46), 54.4% (n = 118) and 22.1% (n = 48) had clear, mild, moderate, and severe AD, respectively. We found that the average total, direct medical, direct non-medical and indirect annual costs per patients were €4,331, €1,136, €747, and €2450, respectively, with absenteeism and presenteeism being the main cost drivers, accounting for 24% and 29% of the total cost of AD. A one-year longer disease duration led to, on average, 1.6%, and 4.2% increase in total and direct non-medical costs, respectively. Patients with worse health-related quality of life (higher DLQI score) had significantly higher total, direct medical, direct non-medical costs, and indirect costs. CONCLUSIONS: Our results indicate a substantial economic burden of AD from a societal perspective, mainly driven by productivity losses.

Analyzing the Pain/Discomfort and Anxiety/Depression Composite Domains and the Meaning of Discomfort in the EQ-5D: A Mixed-Methods Study.

OBJECTIVES: The EQ-5D has 2 composite domains: pain/discomfort (PD) and anxiety/depression (AD). This study aims to explore how respondents use the composites to self-report health and what the meaning of discomfort is in the EQ-5D for the general public. METHODS: Both qualitative and quantitative data were collected in an online cross-sectional survey involving a nationally representative general population sample in Hungary (n = 1700). Respondents completed the 5-level version of EQ-5D, followed by the composites split into individual subdomains. Open-ended questions were asked to explore respondents' interpretations and experiences of discomfort. RESULTS: Six different response behaviors were identified in the composites: "uniform" (21%-32%), "most severe" (30%-34%), "least severe" (16%-23%), "average" (2%-4%), "synergistic" (4%-5%), and "inconsistent" (13%-15%). Compared with the individual subdomains, many respondents under-reported their problems on both composites (PD 16%-22% and AD 6%-13%, P < .05). In respondents who scored differently in the 2 separate domains, mainly problems with the first subdomain determined responses in the composites (PD 66% and AD 61%). The discomfort subdomain in the EQ-5D captured more than 100 different problems, including pain, nonpain physical discomfort (eg, tiredness, dizziness, and nausea), and psychological discomfort (eg, anxiety, nervousness, and sadness). Women, older adults, and those in worse general health status more often considered discomfort as pain (P < .05). CONCLUSIONS: We found empirical evidence of measurement error in the composite responses on the EQ-5D, including under- and inconsistent reporting, ordering effects, potential differential item functioning, and interdomain dependency. Our findings contribute new knowledge to the development of new and refinement of existing self-reported health status instruments, also beyond the EQ-5D.

Assessment of health state utilities in dermatology: an experimental time trade-off value set for the dermatology life quality index.

BACKGROUND: Dermatology Life Quality Index (DLQI) scores are used in many countries as access and reimbursement criteria for costly dermatological treatments. In this study we examined how time trade-off (TTO) utility valuations made by individuals from the general population are related to combinations of DLQI severity levels characterizing dermatologically relevant health states, with the ultimate purpose of developing a value set for the DLQI. METHODS: We used data from an online cross-sectional survey conducted in Hungary in 2020 (n = 842 after sample exclusions). Respondents were assigned to one of 18 random blocks and were asked to provide 10-year TTO valuations for the corresponding five hypothetical health states. To analyze the relationship between DLQI severity levels and utility valuations, we estimated linear, censored, ordinal, and beta regression models, complemented by two-part scalable models accommodating heterogeneity effects in respondents' valuation scale usage. Successive severity levels (0-3) of each DLQI item were represented by dummy variables. We used cross-validation methods to reduce the initial set of 30 dummy variables and improve model robustness. RESULTS: Our final, censored linear regression model with 13 dummy variables had R2 = 0.136, thus accounting for 36.9% of the incremental explanatory power of a maximal (full-information) benchmark model (R2 = 0.148) over the uni-dimensional model (R2 = 0.129). Each DLQI item was found to have a negative effect on the valuation of health states, yet this effect was largely heterogeneous across DLQI items, and the relative contribution of distinctive severity levels also varied substantially. Overall, we found that the social/interpersonal consequences of skin conditions (in the areas of social and leisure activities, work and school, close personal relationships, and sexuality) had roughly twice as large disutility impact as the physical/practical aspects. CONCLUSIONS: We have developed an experimental value set for the DLQI, which could prospectively be used for quantifying the quality-adjusted life years impact of dermatological treatments and serve as a basis for cost-effectiveness analyses. We suggest that, after validation of our main results through confirmatory studies, population-specific DLQI value sets could be developed and used for conducting cost-effectiveness analyses and developing financing guidelines in dermatological care.

A qualitative investigation of the relevance of skin irritation and self-confidence bolt-ons and their conceptual overlap with the EQ-5D in patients with psoriasis.

OBJECTIVES: A number of bolt-ons have been proposed for the EQ-5D, including two psoriasis-specific bolt-ons, skin irritation and self-confidence. The study investigates and compares the relevance and comprehensiveness of these psoriasis-specific bolt-ons and the EQ-5D-5L and explores the potential conceptual overlaps between the existing five dimensions and the two bolt-ons. METHODS: Psoriasis patients were purposively sampled according to age and gender. Semi-structured interviews, where participants were asked to complete the EQ-5D-5L and the bolt-ons while thinking aloud, were conducted. Probes were used to investigate the thought processes of patients regarding the dimensions, wording, recall period and relevant concepts not captured by the EQ-5D-5L and bolt-ons. Data were analysed thematically. A focus group was used to confirm the findings. RESULTS: Overall, 16 patients completed the interviews. Sixteen and fifteen patients considered skin irritation and self-confidence relevant areas to describe psoriasis problems. Three patients considered itching a form of discomfort, and thus, pointed out a potential overlap between pain/discomfort and skin irritation. Twelve patients reported overall 10 general health- or psoriasis-related concepts that are not captured by the EQ-5D-5L, including itching, social relationships and sex life. Eleven patients reported that the recall period of the EQ-5D-5L might be subject to bias because of the daily or within-day fluctuations of their symptoms. CONCLUSIONS: The skin irritation and self-confidence bolt-ons contribute to improve content validity of the EQ-5D-5L in patients with psoriasis. The qualitative approach taken in this study expands the existing methodological framework for the development and testing validity of bolt-ons for the EQ-5D.

Measurement properties of the ICECAP-A capability well-being instrument among dermatological patients.

BACKGROUND: Capability well-being captures well-being based on people's ability to do the things they value in life. So far, no capability well-being measures have been validated in dermatological patients. OBJECTIVES: To validate the adult version of the ICEpop CAPability measure (ICECAP-A) in patients with dermatological conditions. We aimed to test floor and ceiling effects, structural, convergent and known-group validity, and measurement invariance. METHODS: In 2020, an online, cross-sectional survey was carried out in Hungary. Respondents with self-reported physician-diagnosed dermatological conditions completed the ICECAP-A, Satisfaction with Life Scale (SWLS), WHO-5 Well-Being Index and two dermatology-specific measures, Dermatology Life Quality Index (DLQI) and Skindex-16. RESULTS: 618 respondents (mean age 51 years) self-reported a physician-diagnosed dermatological condition, with warts, eczema, onychomycosis, acne and psoriasis being the most common. ICECAP-A performed well with no floor and mild ceiling effects. The violation of local independence assumption was found between the attributes of 'attachment' and 'enjoyment'. ICECAP-A index scores correlated strongly with SWLS and WHO-5 (rs = 0.597-0.644) and weakly with DLQI and Skindex-16 (rs = - 0.233 to - 0.292). ICECAP-A was able to distinguish between subsets of patients defined by education and income level, marital, employment and health status. Multigroup confirmatory factor analysis indicated measurement invariance across most of these subgroups. CONCLUSIONS: This is the first study to validate a capability well-being measure in patients with dermatological conditions. The ICECAP-A was found to be a valid tool to assess capability well-being in dermatological patients. Future work is recommended to test measurement properties of ICECAP-A in chronic inflammatory skin conditions.

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.

A Rasch model analysis of two interpretations of 'not relevant' responses on the Dermatology Life Quality Index (DLQI).

PURPOSE: Eight of the ten items of the Dermatology Life Quality Index (DLQI) have a 'not relevant' response (NRR) option. There are two possible ways to interpret NRRs: they may be considered 'not at all' or missing responses. We aim to compare the measurement performance of the DLQI in psoriasis patients when NRRs are scored as '0' (hereafter zero-scoring) and 'missing' (hereafter missing-scoring) using Rasch model analysis. METHODS: Data of 425 patients with psoriasis from two earlier cross-sectional surveys were re-analysed. All patients completed the paper-based Hungarian version of the DLQI. A partial credit model was applied. The following model assumptions and measurement properties were tested: dimensionality, item fit, person reliability, order of response options and differential item functioning (DIF). RESULTS: Principal component analysis of the residuals of the Rasch model confirmed the unidimensional structure of the DLQI. Person separation reliability indices were similar with zero-scoring (0.910) and missing-scoring (0.914) NRRs. With zero-scoring, items 6 (sport), 7 (working/studying) and 9 (sexual difficulties) suffered from item misfit and item-level disordering. With missing-scoring, no misfit was observed and only item 7 was illogically ordered. Six and three items showed DIF for gender and age, respectively, that were reduced to four and three by missing-scoring. CONCLUSIONS: Missing-scoring NRRs resulted in an improved measurement performance of the scale. DLQI scores of patients with at least one vs. no NRRs cannot be directly compared. Our findings provide further empirical support to the DLQI-R scoring modification that treats NRRs as missing and replaces them with the average score of the relevant items.

The measurement performance of the EQ-5D-5L versus EQ-5D-3L in patients with hidradenitis suppurativa.

PURPOSE: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that affects up to 1% of the population in Europe. The EQ-5D is the most commonly used generic instrument for measuring health-related quality of life among HS patients. This study aims to compare the measurement properties of the two adult versions of EQ-5D (EQ-5D-3L and EQ-5D-5L) in patients with HS. METHODS: We recruited 200 consecutive patients with HS (mean age 37 years, 38% severe or very severe HS) to participate in a multicentre cross-sectional survey. Patients completed the EQ-5D-3L, EQ-5D-5L, Dermatology Life Quality Index (DLQI) and Skindex-16 questionnaires. RESULTS: More than twice as many different health state profiles occurred in the EQ-5D-5L compared to the EQ-5D-3L (101 vs. 43). A significant reduction in ceiling effect was found for the mobility, self-care and usual activities dimensions. A good agreement was established between the EQ-5D-3L and EQ-5D-5L with an intraclass correlation coefficient of 0.872 (95% CI 0.830-0.903; p < 0.001) that was confirmed by a Bland-Altman plot. EQ-5D-5L improved both the absolute and relative informativity in all dimensions except for anxiety/depression. EQ-5D-3L and EQ-5D-5L demonstrated similar convergent validity with DLQI and Skindex-16. EQ-5D-5L was able to better discriminate between known groups of patients based on the number of comorbidities and disease severity (HS-Physician's Global Assessment). CONCLUSION: In patients with HS, the EQ-5D-5L outperformed the EQ-5D-3L in feasibility, ceiling effects, informativity and known-groups validity for many important clinical characteristics. We recommend using the EQ-5D-5L in HS patients across various settings, including clinical care, research and economic evaluations.