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

Comparing EQ-5D-5L, PROPr, SF-6D and TTO utilities in patients with chronic skin diseases

OBJECTIVES

We aim to compare the measurement properties of three indirect (EQ-5D-5L, PROPr, SF-6D) and one direct (time trade-off, TTO) utility assessment methods in patients with chronic skin diseases.

METHODS

120 patients with physician-diagnosed chronic skin diseases (psoriasis 39%, atopic dermatitis 27%, acne 19%) completed a cross-sectional survey. Respondents completed the EQ-5D-5L, PROMIS-29+2 and SF-36v1 questionnaires and a 10-year TTO task for own current health. Utilities were computed using the US value sets. Ceiling, convergent and known-group validity were compared across the utilities derived with these four methods. Known-groups were defined based on general, physical and mental health. The agreement between utilities was assessed using intraclass correlation coefficients (ICC).

RESULTS

Mean utilities for the EQ-5D-5L, PROPr, SF-6D and TTO were 0.79, 0.47, 0.76 and 0.89. In corresponding order, the ceiling was 28%, 0%, 2% and 65%. The SF-6D showed excellent agreement with the EQ-5D-5L (ICC = 0.770). PROPr demonstrated poor agreement with the EQ-5D-5L (ICC = 0.381) and fair with SF-6D utilities (ICC = 0.445). TTO utilities showed poor agreement with indirectly assessed utilities (ICC = 0.058-0.242). The EQ-5D-5L better discriminated between known groups of general and physical health, while the SF-6D and PROPr outperformed the EQ-5D-5L for mental health problems.

CONCLUSION

There is a great variability in utilities across the four methods in patients with chronic skin conditions. The EQ-5D-5L, despite its higher ceiling, appears to be the most efficient in discriminating between patient groups for physical health aspects. Our findings inform the choice of instrument for quality-adjusted life year calculations in cost-utility analyses.

Developing and testing a patient-reported outcome measure for patients with sleep disturbances using EQ-5D and condition-specific bolt-ons: a mixed method study

OBJECTIVES

The EQ-5D-5L may not adequately capture the health-related quality of life in patients with sleep disturbances. We examined the psychometric properties of a hybrid PROM comprising a module of four sleep-related bolt-ons and EQ-5D-5L.

METHODS

We employed a sequential exploratory mixed method by first qualitatively testing the face validity of "sleep", "cognition", "tiredness" and "relationship" and refining these bolt-ons through in-depth interviews with 23 patients and clinicians. We then quantitatively assessed their performance by administering the four bolt-ons, appended to EQ-5D-5L, and three condition-specific patient-reported outcome measures (cPROMs) during two clinical visits of patients with respiratory-related sleep disorders. We compared ceiling effects and construct validity of EQ-5D-5L with and without the bolt-ons by testing a priori hypotheses about the cPROMs and polysomnographic characteristics via correlation and areas under the curves (AUC) analyses, respectively. We examined their responsiveness among "treated/improved" participants using standardized response means (SRM) and AUC analysis, and reliability among "untreated/no change" participants using intra-class correlation coefficient (ICC) or Cohen's Kappa (k).

RESULTS

110 participants (mean [SD] age: 47[13]) were recruited and 90 returned for their review assessments (mean [SD] interval: 2.2 [2.1] months). The bolt-ons led to a reduction of 42.7% in ceiling effects. The bolt-ons were better correlated with cPROMs and exhibited higher discriminatory power and responsiveness, with comparable reliability to EQ-5D-5L. A combined module of the four bolt-ons provided better results than individual bolt-ons.

CONCLUSIONS

A "hybrid" PROM of sleep bolt-ons module added to EQ-5D-5L improved its psychometric properties among patients with sleep disturbances.

EuroQol data for assessment of population health needs and instrument evaluation (EQ-DAPHNIE): a study for enhancing population health assessment

BACKGROUND

Methods for collecting self-reported health status measures in population health surveys vary significantly across countries, presenting challenges to comparability. The EuroQol Data for Assessment of Population Health Needs and Instrument Evaluation (EQ-DAPHNIE) project aims to address this issue by developing infrastructure to generate representative datasets across multiple countries. This initiative aims to standardize data collection methodologies and to evaluate the performance of various health status measures, providing a foundation for reliable population health assessments. This paper describes the rationale, design and data collection methods for the EQ-DAPHNIE project.

METHODS/DESIGN

EQ-DAPHNIE employs a cross-sectional online survey design targeting the general adult population across various countries. Participants were recruited through an online panel provider. Each country had a target sample of 4500 responses, with quota sampling to ensure representativeness based on age, sex, income, region, and language. The survey collected comprehensive data on social determinants of health at both individual and neighbourhood levels. Participation was voluntary, and measures were taken to maintain data anonymity and ensure data quality through pre-testing and various quality assurance approaches.

DISCUSSION

The EQ-DAPHNIE project represents a significant advancement in generating large, representative, and comparable population health datasets across multiple countries. By employing precise sampling strategies, robust recruitment and data collection methods, and rigorous quality control measures, the project aims to provide a valuable resource for assessing and understanding population health and evaluating various health-related quality of life (HRQoL) and wellbeing instruments.

A Comparative Study of Health and Well-Being Measures in Ireland Using EQ Health and Well-Being (EQ-HWB) and its Short Version, EQ-5D-5L, and ICEpop Capability Measure for Adults (ICECAP-A)

OBJECTIVES

The EQ Health and Wellbeing (EQ-HWB) is a new experimental measure of health and well-being, having been validated in an increasing number of countries and languages. This study aims to examine the psychometric properties of the EQ-HWB and its short version (EQ-HWB-S) in Ireland and compare them with the EQ-5D-5L and ICEpop Capability Measure for Adults (ICECAP-A).

METHODS

A secondary analysis of cross-sectional data from a 2023 Irish general population survey (n = 1220). The survey included the EQ-HWB, EQ-5D-5L, ICECAP-A, and socioeconomic and health-related questions. EQ-HWB-S responses were derived from the EQ-HWB. The UK or Irish value sets were used for each measure to compute index values. Ceiling effects, convergent, divergent validity, and known-group validity were assessed and exploratory factor analysis was conducted.

RESULTS

Mean index values were 0.755, 0.760 to 0.830, and 0.807 for the EQ-HWB-S, EQ-5D-5L, and ICECAP-A, respectively. Ceiling effects were 3%, 7%, 23%, and 15% for EQ-HWB, EQ-HWB-S, EQ-5D-5L, and ICECAP-A. EQ-HWB-S index values correlated strongly with EQ-5D-5L (r = 0.740-0.759) and ICECAP-A (r = 0.604) index values. All measures demonstrated good known-group validity for health-related variables, with EQ-5D-5L performing best overall. Factor analysis identified 5 factors: psychosocial health, pain and discomfort, sensory and physical functioning, capability well-being, and positive psychological states. Feeling settled and secure was the only ICECAP-A item that loaded onto the same factor (psychosocial health) as any of the EQ-HWB items.

CONCLUSIONS

To our knowledge, this is the first study to compare the measurement performance of EQ-HWB and EQ-HWB-S with ICECAP-A. The EQ-HWB and EQ-HWB-S showed good psychometric performance in an Irish population sample. Limited overlap was observed between EQ-HWB and ICECAP-A well-being concepts.

Development and Testing of the Psychometric Properties of 20 Bolt-On Items for the EQ-5D-5L Across 31 Rare Diseases

OBJECTIVES

Our objective was to develop and assess the psychometric properties of relevant bolt-on items for the EQ-5D-5L in patients with rare diseases (RDs).

METHODS

Nineteen new EQ-5D-5L bolt-ons were developed based on literature review, expert input, and qualitative interviews and focus groups with patients, caregivers, and representatives of patient associations. A nationwide, cross-sectional, web-based survey in China included patients or caregivers of patients with 31 RDs in China (n = 9190). In each RDs, participants completed the EQ-5D-5L and 3 of 20 (1 existing and 19 newly developed) bolt-ons. Ceiling, explanatory power, convergent, divergent, and known-group validity were examined.

RESULTS

Among the bolt-ons, itching had the lowest ceiling (6.5%), whereas social relationships had the highest (42.2%). The absolute reduction in the ceiling of the EQ-5D-5L with the addition of any bolt-ons was limited, ranging from 0 (respiratory problems) to 8.3% points (isolation). Dignity and vitality resulted in the largest increase in explained variance in EQ VAS. The isolation, fertility, and visual acuity bolt-ons showed good divergent validity from the EQ-5D-5L items. There was strong convergent validity between SF-12 and conceptually related bolt-ons (eg, physical health composite and muscle problems bolt-on). Various bolt-ons improved the known-groups validity in specific patient groups, eg, Huntington's disease (oral expressions), scleroderma (dexterity), myasthenia gravis (muscle problems), neuromyelitis optica and multiple sclerosis (fatigue), Marfan syndrome (self-image), and Pompe disease (safety).

CONCLUSION

The EQ-5D-5L shows sufficient validity in most RDs, but incorporating relevant, specific bolt-ons could enhance its ability to more comprehensively assess health-related quality of life in these patients.

Exploring the origin and conceptual framework of the EQ VAS

PURPOSE

The objective of this paper is to report on the origin of the EQ VAS and current understanding of the EQ VAS conceptual framework via a literature search based on the snowball approach.

METHODS

A review was conducted in two steps: (1) a citation search and (2) a search of the EuroQol group's grey literature.

RESULTS

The findings indicate that the EQ VAS was originally designed as a warm-up task for valuing hypothetical health states. The characters of the EQ VAS reflect its valuation origin, such as drawing a line (the previous version), vertical orientation, and choice of end labels. None of these design elements of the EQ VAS were chosen for the purpose of measuring self-reported overall health. Despite this, the EQ VAS proves to be a valid self-reported health status measure with its psychometric properties demonstrated in various general and clinical populations. We found a dearth of literature addressing the conceptual framework of EQ VAS as a measure of self-rated overall health.

CONCLUSION

With its potential as a powerful measure of overall health, further research into EQ VAS design, conceptual framework and empirical function is warranted.

Psychometric Properties of the Modified EQ Health and Wellbeing and its Shorter Version in a General Chinese Population: A Comparative Analysis With EQ-5D-5L, SF-6Dv2, ICEpop CAPability measure for Adults, Short Version of Warwick-Edinburgh Mental Wellbeing Scale, and World Health Organization Well-Being Index 5-Item

OBJECTIVES

The Modified EQ Health and Wellbeing (EQ-HWB) and its shorter version (EQ-HWB-S) are new health and well-being measures nearing finalization. Since the 2022 version, the development group has proposed revisions to the item order, response levels, and wording. This study aimed to assess the psychometric properties of the modified Simplified Chinese EQ-HWB and EQ-HWB-S and compare their performance with other measures.

METHODS

The data were collected through a web-based survey of the Chinese general population (n = 1053). Outcome measures included the modified EQ-HWB, EQ-5D-5L, SF-6Dv2, ICEpop CAPability measure for Adults, short version of Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS), and World Health Organization Well-Being Index 5-Item. We examined psychometric properties, such as distributional characteristics (ceiling and floor), convergent (correlations), known-group (effect sizes), and structural validity (principal component analysis).

RESULTS

At the instrument level, neither the modified EQ-HWB nor EQ-HWB-S showed ceiling effect. The response distribution of the 3 items (enjoyable activities, excluded by others, and negative feelings about oneself) modified from positively to negatively framed was in the range of the other items. The EQ-HWB "getting around inside or outside," "day-to-day activities," and "enjoyable activities" items showed only moderate correlations with the corresponding EQ-5D-5L and SF-6Dv2 dimensions (rho = 0.31-0.36). The EQ-HWB items mainly loaded on separate factors from the ICEpop CAPability measure for Adults, short version of Warwick-Edinburgh Mental Wellbeing Scale, and World Health Organization Well-Being Index 5-Item items. The EQ-HWB effectively differentiated between sociodemographic and health-related known groups with larger effect sizes than the EQ-HWB-S.

CONCLUSIONS

The modified EQ-HWB and EQ-HWB-S demonstrated mixed psychometric performance. Several modified items showed improved distributional characteristics compared with earlier findings with the original EQ-HWB. However, item-level correlations were somewhat weaker than those reported in previous studies using the original version.

Qualitative evidence on EQ-5D-5L skin irritation and self-confidence bolt-ons in Darier's disease and Hailey-Hailey disease

OBJECTIVES

Limited evidence is available about the content validity of the EQ-5D-5L in rare skin fragility disorders. Previous research has demonstrated that the skin irritation and self-confidence additional dimensions (bolt-ons) improve the content validity of the EQ-5D-5L in psoriasis and atopic dermatitis. Our aim was to investigate the content validity of the EQ-5D-5L and the two bolt-ons in Darier's disease and Hailey-Hailey disease.

METHODS

In 2023, we conducted qualitative, semi-structured interviews with 15 adult patients at a university dermatology clinic. Patients completed the EQ-5D-5L with two bolt-ons using a think-aloud technique. We used probing questions to explore the relevance, comprehensiveness and comprehensibility. Thematic analysis was applied to analyze the transcripts from the interviews.

RESULTS

Most patients found both the EQ-5D-5L and the two bolt-ons comprehensible and relevant to their disease. All patients preferred the EQ-5D-5L with the two bolt-ons over the EQ-5D-5L alone. Twelve potential missing concepts were identified after the EQ-5D-5L + bolt-ons, but only financial impact and sex life were identified by more than one patient. Only one patient reported a conceptual overlap between the skin irritation bolt-on and the pain/discomfort dimension.

CONCLUSIONS

Our findings suggest that there is no actionable evidence indicating gaps in the content validity of the EQ-5D-5L with two bolt-ons in Darier's and Hailey-Hailey disease. Future studies are encouraged to conduct quantitative psychometric testing of the bolt-ons in this and other chronic dermatological patient populations.

The added value of the cognition, dining, gastrointestinal problems, sleep and tiredness bolt-on dimensions to the EQ-5D-5L in patients with coeliac disease

OBJECTIVES

Multiple studies suggest that the EQ-5D may overestimate health-related quality of life (HRQoL) in patients with coeliac disease (CD). We aimed to develop and psychometrically test potentially relevant bolt-on dimensions to improve the measurement performance of the EQ-5D-5L in CD patients.

METHODS

The development and selection of bolt-ons were informed by a literature review on HRQoL in CD, expert and patient input. A cross-sectional online survey was conducted amongst 312 adult CD patients. Respondents completed the EQ-5D-5L, two condition-specific bolt-ons newly-developed for the present study [dining (DI) and gastrointestinal problems (GI)] and three existing bolt-ons [cognition (CO), sleep (SL) and tiredness (TI)]. The following psychometric properties were tested: ceiling, informativity, convergent and known-group validity, and dimensionality (confirmatory factor analysis).

RESULTS

Adding the TI, SL, GI, DI and CO individual bolt-ons reduced the ceiling of the EQ-5D-5L (39%) to 17%, 23%, 24%, 26% and 37%, respectively. GI excelled with strong convergent validity with the Gastrointestinal Symptom Rating Scale total score (rs=0.71) and improved the discriminatory power for all known-groups. GI was the only bolt-on loading on a different factor from the five core dimensions, whereas the other four bolt-ons loaded onto the same 'psychosocial health' factor as the EQ-5D-5L anxiety/depression dimension.

CONCLUSION

The DI, GI, SL and TI bolt-ons, especially the GI, enhance the validity of EQ-5D-5L in patients with CD, suggesting their value in capturing important HRQoL aspects potentially missed by the five core dimensions. These bolt-ons can be used in sensitivity analyses supporting health technology assessments and subsequent resource allocation decisions.

Psychometric benefits of adding bolt-ons to the EQ-5D-5L in populations undergoing minimally invasive cosmetic procedures

OBJECTIVES

There is growing interest in measuring health outcomes associated with minimally invasive cosmetic procedures (MICPs), such as botulinum toxin and hyaluronic acid injections. However, the EQ-5D may have limited content validity for this purpose. This study aims to psychometrically test five additional dimensions ('bolt-ons') for the EQ-5D-5L in individuals planning or undergoing MICPs.

METHODS

In 2023, a cross-sectional, online survey was conducted with 149 women planning MICPs and 215 who had recently undergone them. Respondents completed the EQ-5D-5L, five bolt-ons (skin irritation, self-confidence, sleep, social relationships, tiredness), the Rosenberg Self-Esteem Scale (RSES) and the Brief Fear of Negative Evaluation Scale-Straightforward Items (BFNE-S). The following psychometric properties were tested for the EQ-5D-5L + bolt-on(s): ceiling, convergent and divergent validity, explanatory power and known-groups validity.

RESULTS

Adding tiredness (22%), self-confidence (23%) or sleep bolt-ons (27%) substantially reduced the ceiling of the EQ-5D-5L (47%). The self-confidence and social relationships bolt-ons showed a moderate or strong correlation with the RSES and BFNE-S total scores (-0.462 to -0.679). The tiredness and self-confidence bolt-ons improved the EQ-5D-5L's explained variance in EQ VAS scores from 37% to 45%. The self-confidence and social relationships bolt-ons improved the EQ-5D-5L's discrimination between known groups based on self-esteem and bodily appearance (relative efficiency: 2.72 to 2.82).

CONCLUSIONS

Relevant bolt-ons substantially enhance the psychometric performance of the EQ-5D-5L in MICP populations. The self-confidence and tiredness bolt-ons may be recommended as primary choices for use alongside the EQ-5D-5L, both in clinical studies and as part of sensitivity analyses in economic evaluations of MICPs.

Development of updated population norms for the SF-36 for Hungary and comparison with 1997-1998 norms

BACKGROUND

Hungarian SF-36 population norm data were last collected in 1997-1998 and have not been updated since, reducing their relevance and limiting their usability and comparability. This study aimed to establish contemporary normative data for the SF-36 domain and standardised summary scores in Hungary and compare them to the previous population norms.

METHODS

An online cross-sectional survey, including the SF-36v1, was conducted among 1,700 members of the Hungarian adult general population in 2020. The sample demonstrated good representativeness across key sociodemographic characteristics. Normative data were calculated for domains using raw scores and for summary scores using country-specific factor score coefficients derived from exploratory factor analysis. Multivariate linear regression models were performed to examine the association of domain and summary scores with sociodemographic and health-related characteristics. Raw domain scores were compared with the 1997-1998 norms.

RESULTS

Males reported higher scores (better health) in seven out of eight domains (p < 0.001). Mean standardised PCS scores decreased, whereas MCS scores increased with age (p < 0.001). Compared to the 1997-1998 population norms, the 18-24 and 25-34 age groups reported lower, while the 65 + age group reported higher scores in all eight domains. Higher scores were reported in 2020 from the 35-44 age group onward on the role physical, bodily pain, social functioning, and role emotional domains.

CONCLUSIONS

This study established contemporary population norms for the SF-36 in Hungary. Our results highlight the changes in health status in the general population, particularly in young adults, compared to the 1997-1998 population norms, and provide valuable input to inform decision-makers.