The Short Form 6 Dimensions (SF-6D): Development and Evolution.

This paper considers the development and evolution of the short-form 6 dimensions (SF-6D), a generic preference-weighted measure consisting of a health classification with accompanying value set that was developed from one of the widest used health related quality of life measures, the SF-36 health survey. This enabled health state utility values to be directly generated from SF-36 and SF-12 data for a range of purposes, including to produce quality adjusted life years for use in economic evaluation of healthcare interventions across a range of different conditions and treatments. This paper considers the rationale for the development of the measure, the development process, performance and how the SF-6D has evolved since its conception. This includes the development of an updated version, SF-6D version 2 (SF-6Dv2), which was generated to deal with some criticisms of the first version, and now includes a standalone version for inclusion in studies without relying on use of SF-36 or SF-12. Valuation methods have also evolved, from standard gamble in-person interviews to online discrete choice experiment surveys. International work related to the SF-6Dv1 and SF-6Dv2 is considered. We also consider recommendations for use, highlighting key psychometric evidence and reimbursement agency recommendations.

Testing the psychometric characteristics of EQ-5D-5L and respiratory bolt-ons using a sample of the Australian population.

PURPOSE: The EQ-5D has been used to assess health related quality of life (HRQoL) in respiratory conditions. However, the core descriptive system may not be sensitive to all the HRQoL impacts of these conditions. To increase the sensitivity of the descriptive system, two respiratory specific bolt-ons, have been developed. Psychometric assessment of the bolt-ons in comparison to other validated instruments is required to facilitate their use. Therefore, the aim of this study is to test the psychometric characteristics of the EQ-5D-5L + R using a large dataset collected in Australia. METHODS: A cross-sectional online survey was used to recruit adult respondents (≥ 18 years) representative of the Australian population. Descriptive and psychometric analyses were used to understand the performance of the EQ-5D-5L and bolt-ons in comparison to other validated instruments. The construct validity was estimated using correlations. Known-group validity was tested to determine the sensitivity of the instruments to differences across different severity groups. RESULTS: Overall 10,033 respondents (52% female) completed the survey, of which 300 had a respiratory condition. There were moderate to high correlation between bolt-ons with EQ-5D-5L and WHODAS. The EQ-5D-5L + bolt-ons slightly reduced the ceiling effect in comparison to the EQ-5D-5L. The effect size was larger for people with respiratory conditions than people who did not have a respiratory condition. CONCLUSION: The results show that adding the respiratory bolt-on to the EQ-5D-5L might slightly improve the instruments descriptive sensitivity. The choice of bolt-on may be driven by whether overall problems or limitations are being measured.

Delineating Care Recipient Burden Constructs: Development and Validation of the CARE-2B Scale for Care Recipient Self-Perceived Burden and Proxy Assessment of Caregiver Burden.

BACKGROUND AND OBJECTIVES: Care Recipient Self-Perceived Burden (CR-SPB) to Caregivers is an important but overlooked aspect within the caregiver-care recipient relationship. This study aimed to 1) develop and validate the CARE-2B (Care Recipient's Two Burden) Scale, assessing both CR-SPB and their proxy assessment of caregiver burden (Proxy-CB); 2) examine whether the CR-SPB and Proxy-CB differ from caregiver burden's own assessment and other health and social care constructs. RESEARCH DESIGN AND METHODS: Data were collected from 504 caregiver-care recipient dyads in the US using an online panel between August 2022 and February 2023. Care recipients completed the CARE-2B Scale, which includes two subscales: their self-perceived burden (CR-SPB) and their proxy assessment of caregiver burden (Proxy-CB). Care recipients also completed measures related to health, well-being: SPB-scale, EQ-5D-5L, and EQ-HWB. Caregivers completed CarerQoL and ASCOT-Carer. Psychometric analysis included exploratory and confirmatory factor analysis, item response theory (IRT), and construct validity. RESULTS: CR-SPB correlated strongly with the SPB-Scale (r=0.73), while Proxy-CB correlated more strongly with caregiver-reported burden (r=0.61). Both CR-SPB and Proxy-CB items demonstrated good discrimination and information coverage in IRT analysis. EFA further supported the distinctiveness of CR-SPB and Proxy-CB, with CR-SPB items loading on a separate factor from caregiver burden and health constructs, while Proxy-CB aligned with caregiver-reported burden. DISCUSSION AND IMPLICATIONS: The CARE-2B Scale innovatively assesses both CR-SPB and Proxy-CB from the care recipient's perspective, providing new insights into the caregiving relationship. This dual-perspective measure has implications for enhancing care strategies for individuals with chronic conditions or disabilities and their caregivers.

Appropriateness of the EQ-HWB for Use in Residential Aged Care: A Proxy Perspective.

BACKGROUND AND OBJECTIVE: The EQ Health and Wellbeing (EQ-HWB) is a new generic quality-of-life measure for use in evaluating interventions in health, public health and social care. This study aimed to explore proxies' views regarding the appropriateness of the EQ-HWB for measuring residents' quality of life living in residential aged care facilities. METHODS: Qualitative think-aloud and semi-structured interviews were conducted with family members and aged care staff across three facilities in Melbourne, Australia. Proxies completed the 25-item EQ-HWB proxy version 2 (i.e. proxy-person perspective) whilst talking through the reasons for choosing their response. All interviews were audio-recorded and transcribed verbatim. A thematic analysis was used for data analysis. RESULTS: The sample included 29 proxies; nine family members and 20 aged care staff. The first theme summarised proxies' ability to proxy report residents' health and well-being using the EQ-HWB, which highlighted challenges with adherence to the proxy perspective, proxies' limited knowledge about residents, disagreement with residents' self-evaluation and use of heuristics. The second theme reflected feedback on the suitability of the EQ-HWB for use in residential aged care. Although proxies perceived that the EQ-HWB covered important domains, there were concerns about ambiguity, inappropriate examples, double-barrelled items and perceived repetition. Suggestions were made to improve the response options, comprehensiveness, recall period, layout and instructions of the questionnaire. CONCLUSIONS: While the EQ-HWB captures domains relevant to residential aged care, modifications to item wording and examples are necessary to improve its appropriateness. Use of the proxy-person perspective revealed some challenges that require further consideration.

An EQ-5D-5L Value Set for Ghana Using an Adapted EuroQol Valuation Technology Protocol.

OBJECTIVES: Ghana's economic evaluation reference case recommends quality-adjusted life-years as an outcome measure for the conduct of cost-utility analysis. There is no Ghanaian value set available to be used in estimating quality-adjusted life-years. This study aimed to develop a value set for Ghana using the EQ-5D-5L instrument. METHODS: Face-to-face preference data were collected from 300 adults across 3 regions of Ghana using the adapted version of the EuroQol valuation technology (EQ-VT) standardized valuation protocol; with composite time-trade-off (cTTO) and discrete-choice experiments (DCEs) elicitation techniques. The cTTO and DCE data were modeled individually or together to provide complementary results on respondents' utility preferences. Models explored were generalized least squares, Tobit, heteroskedastic, logit, and hybrid. The best-fitting model for the value set was selected based on its logical consistency, accounting for left-censored and heteroscedasticity data, and the statistical significance of parameters. RESULTS: The 300 interviews provided 4500 cTTO responses and 4200 DCE responses. The preferred model chosen for the Ghana value set was the Hybrid Tobit random effect heteroscedastic-constrained model. The predicted value for the worst attainable health state (55555) was -0.493 and the best health state (11112) was 0.969. The largest decrement was registered for level 5 mobility (0.369) followed by pain/discomfort (0.312), self-care (0.273), anxiety/depression (0.271), and usual activities (0.268). CONCLUSIONS: This is the first Ghanaian EQ-5D-5L value set based on social preference derived from a nationally representative sample. The value set will play a key role in the use of economic evaluation studies to inform priority setting in Ghana where different health technologies can be compared.

Estimating Australian Population Utilities for Inherited Retinal Disease Using Time Trade-Off.

PURPOSE: Inherited retinal disease (IRD) causes progressive loss of visual function, degenerating towards complete blindness. Economic evaluation of gene therapies for rare forms of genetic IRDs have had to rely on health-related quality of life (HR-QoL) estimates from other diseases because there is limited data available for such a rare condition. This study aimed to estimate Australian societal-based utility values for IRD health states that can be used in cost-utility analyses (CUA) using a time trade-off (TTO) protocol adapted from a UK study. METHODS: The EuroQol Valuation Technology (EQVT) protocol composite TTO (cTTO) framework was followed, which includes worse-than-death (WTD) states and quality control (QC) measures. Preferences were collected from a general population sample of 110 Australian adult participants. Five health state vignettes from the UK study which had been validated with patients and clinicians were presented randomly to participants during videoconferencing (VC) interviews with one of four interviewers. Technical and protocol feasibility were assessed in a pilot of 10 interviews. QC measures were used to monitor interviewers' performance during the study. RESULTS: One participant withdrew consent. The final analysis was conducted on 109 respondents (including 4 non-traders). The average time to complete the interview was 44.2 minutes (SD 8.7). Participants reported mean visual analogue scale (VAS) scores between 63.15 for 'moderate impairment' and 17.98 for 'hand motion' to 'no light perception'. Mean health state utilities (HSU) varied between 0.76 (SD 0.26) in 'moderate impairment', and 0.20 (SD 0.58) in 'hand motion' to 'no light perception'. Of all HSU evaluations, 14% were considered WTD which most commonly occurred in the most severe visually impaired health state. CONCLUSION: This study provides valuable information on HSUs across a range of IRD health states from the Australian general population perspective. The utilities obtained in this study can be used as inputs into CUA of IRD therapies.

Valuing quality of life for economic evaluations in cancer: navigating multiple methods.

INTRODUCTION: Utility values offer a quantitative means to evaluate the impact of novel cancer treatments on patients' quality of life (QoL). However, the multiple methods available for valuing QoL present challenges in selecting the most appropriate method across different contexts. AREAS COVERED: This review provides cancer clinicians and researchers with an overview of methods to value QoL for economic evaluations, including standalone and derived preference-based measures (PBMs) and direct preference elicitation methods. Recent developments are described, including the comparative performance of cancer-specific PBMs versus generic PBMs, measurement of outcomes beyond health-related QoL, and increased use of discrete choice experiments to elicit preferences. Recommendations and considerations are provided to guide the choice of method for cancer research. EXPERT OPINION: We foresee continued adoption of the QLU-C10D and FACT-8D in cancer clinical trials given the extensive use of the EORTC QLQ-C30 and FACT-G in cancer research. While these cancer-specific PBMs offer the convenience of eliciting utility values without needing a standalone PBM, researchers should consider potential limitations if they intend to substitute them for generic PBMs. As the field advances, there is a greater need for consensus on the approach to selection and integration of various methods in cancer clinical trials.

Creating an SF-6Dv2 social value set for New Zealand.

The SF-6D health descriptive system and its second version published in 2020, the SF-6Dv2, is used worldwide for valuing health-related quality of life (HRQoL) for economic evaluation and measuring patient-reported health outcomes. In this study, a valuation tool was developed and applied to create a social value set, comprising 18,750 health state values, for the SF-6Dv2 for New Zealand (NZ). This tool was adapted and extended from the one used to create a social value set for the EQ-5D-5L, a simpler health descriptive system with fewer dimensions and health states. The tool implements the PAPRIKA method, a type of adaptive discrete choice experiment, and a binary search algorithm to identify health states worse than dead and has extensive data quality controls to ensure the validity and reliability of the social value set derived from participants' personal value sets. The tool, accompanied by a short introductory video designed specifically for the SF-6Dv2, was distributed via an online survey to a large representative sample of adult New Zealanders in June-July 2022. The tool's data quality controls enabled participants who failed to understand or sincerely engage with the valuation tasks to be identified and excluded, resulting in the participants being pared down to a sub-sample of 2985 'high-quality' participants whose personal value sets were averaged for the social value set. These results, including participants' positive feedback, demonstrate the feasibility and acceptability of using the tool to value larger health descriptive systems such as the SF-6Dv2. Having successfully created an SF-6Dv2 social value set for NZ, the valuation tool can be readily applied to other countries, used to generate personal value sets for personalised medicine and adapted to create value sets for other health descriptive systems.

Putting a Dollar Value on Informal Care Time Provided to People Living With Dementia: A Discrete Choice Experiment.

OBJECTIVES: Informal care represents a significant cost driver in dementia but monetizing informal care hours to inform cost-of-illness or economic evaluation studies remains a challenge. This study aimed to use a discrete choice experiment to estimate the value of informal care time provided to people with dementia in Australia accounting for positive and negative impacts of caregiving. METHODS: Attributes and levels were derived from a literature review, interviews with carers, and advice received from an advisory group. Attributes included 4 positive and negative caregiving experiences, in addition to "hours of care provided" and the "monetary compensation from the government." A D-efficient design was constructed with 2 generic alternatives that represented hypothetical informal caregiving situations. The discrete choice experiment survey was administered online to a representative sample of the Australian general population and a group of informal carers of people with dementia. The willingness to accept estimates were calculated for the 2 samples separately using the mixed logit model in the willingness to pay space. RESULTS: Based on 700 respondents included in the analysis (n = 488 general public, n = 212 informal carers), the mean willingness to accept for an additional hour of informal care, corrected for the positive and negative impacts of informal care, was $21 (95% CI 18-23) for the general public and $20 (95% CI 16-25) for the informal carers sample. CONCLUSION: The estimates generated in this study can be used to inform future cost-of-illness studies and economic evaluations, ensuring that informal care time is considered in future policy and funding decisions.

A Comparison of the Psychometric Properties of the EQ-5D-Y-3L and EQ-5D-Y-5L Using Paediatric Multi-Instrument Comparison (P-MIC) Study Data.

BACKGROUND: The EQ-5D-Y is a generic health-related quality of life (HRQoL) measure suitable for children and adolescents. There are two versions of the instrument, which differ in response levels: the three- (Y-3L) and five-level (Y-5L) versions. The Y-5L has been developed to improve the psychometric performance of the Y-3L. OBJECTIVE: This study aims to assess the psychometric properties of Y-5L and to compare the performance of Y-5L with Y-3L in separate self- and proxy-reported samples. METHODS: Both versions of the instrument were administered to children/adolescents (self-report) or caregivers (proxy-report) of Australian children aged 5-18 years. The data were gathered as part of the Australian Paediatric Multi-Instrument Comparison (P-MIC) study. The Y-5L and Y-3L were evaluated in terms of ceiling effects, criterion validity, inconsistency, informativity, and test-retest reliability in both proxy and self-complete populations. RESULTS: Overall, 5945 respondents completed both the Y-3L and Y-5L, with 2083 proxy and 3862 self-completed responses. Ceiling effects were lower in the Y-5L than the Y-3L. Items from the same domains show the strongest correlation for both samples. Regarding informativity, the Y-5L demonstrated more discriminatory power, indicated by having a higher Shannon diversity index in all domains of the Y-5L compared with the Y-3L. Test-retest showed fair agreement between responses at baseline and follow-up. CONCLUSION: The Y-5L has demonstrated moderate validity and fair reliability for use in measuring HRQoL in children and adolescents, both when self-reported by children or proxy reported. Overall, Y-5L is a dependable and valid extension from the Y-3L.

Comparing Generic Paediatric Health-Related Quality-of-Life Instruments: A Dimensionality Assessment Using Factor Analysis.

BACKGROUND: Widely used generic instruments to measure paediatric health-related quality of life (HRQoL) include the EQ-5D-Y-5L, Child Health Utility 9 Dimension (CHU-9D), Paediatric Quality of Life Inventory (PedsQL) and Health Utilities Index (HUI). There are similarities and differences in the content of these instruments, but there is little empirical evidence on how the items they contain relate to each other, and to an overarching model of HRQoL derived from their content. OBJECTIVE: This study aimed to explore the dimensionality of the instruments using exploratory factor analysis (EFA). METHODS: Data from the Australian Paediatric Multi-Instrument Comparison (P-MIC) Study were used. EQ-5D-Y-5L, CHU-9D, PedsQL and HUI data were collected via proxy or child self-report data. EFA was used to investigate the underlying domain structure and measurement relationship. Items from the four instruments were pooled and domain models were identified for self- and proxy-reported data. The number of factors was determined based on eigenvalues greater than 1. A correlation cut-off of 0.32 was used to determine item loading on a given factor, with cross-loading also considered. Oblique rotation was used. RESULTS: Results suggest a six-factor structure for the proxy-reported data, including emotional functioning, pain, daily activities, physical functioning, school functioning, and senses, while the self-report data revealed a similar seven-factor structure, with social functioning emerging as an additional factor. CONCLUSION: We provide evidence of differences and similarities between paediatric HRQoL instruments and the aspects of health being measured by these instruments. The results identified slight differences between self- and proxy-reported data in the relationships among items within the resulting domains.

Development of algorithms for estimating the Child Health Utility 9D from Caregiver Priorities and Child Health Index of Life with Disability.

PURPOSE: The primary aim was to determine Child Health Utility 9D (CHU9D) utilities from the Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) for non-ambulatory children with cerebral palsy (CP). METHODS: One hundred and eight surveys completed by Australian parents/caregivers of children with CP were analysed. Spearman's coefficients were used to investigate the correlations between the two instruments. Ordinary least square, robust MM-estimator, and generalised linear models (GLM) with four combinations of families and links were developed to estimate CHU9D utilities from either the CPCHILD total score or CPCHILD domains scores. Internal validation was performed using 5-fold cross-validation and random sampling validation. The best performing algorithms were identified based on mean absolute error (MAE), concordance correlation coefficient (CCC), and the difference between predicted and observed means of CHU9D. RESULTS: Moderate correlations (ρ 0.4-0.6) were observed between domains of the CHU9D and CPCHILD instruments. The best performing algorithm when considering the CPCHILD total score was a generalised linear regression (GLM) Gamma family and logit link (MAE = 0.156, CCC = 0.508). Additionally, the GLM Gamma family logit link using CPCHILD comfort and emotion, quality of life, and health domain scores also performed well (MAE = 0.152, CCC = 0.552). CONCLUSION: This study established algorithms for estimating CHU9D utilities from CPCHILD scores for non-ambulatory children with CP. The determined algorithms can be valuable for estimating quality-adjusted life years for cost-utility analysis when only the CPCHILD instrument is available. However, further studies with larger sample sizes and external validation are recommended to validate these findings.

Understanding caregiver burden from multiple perspectives: dyadic agreement between caregiver and care recipient.

PURPOSE: Caregiver burden (CB) is typically self-assessed by caregivers. However, an emerging concept is assessment of CB by the recipients of care, i.e., the patient. The specific objectives are (1) to assess the level of agreement between care recipients' and caregivers' view on CB, across financial, physical, emotional, and social domains; (2) to explore two care recipient perspectives: their self-perceived burden (CR-SPB), and their interpretation of the caregiver's view (Proxy-CB). METHODS: Data were collected from 504 caregiver-care recipient dyads in the U.S. using an online Qualtrics panel. The survey assessed caregiver burden using CarerQol and newly developed items. The level of agreement between responses was quantified using weighted kappa (κ) coefficients for individual items and intraclass correlation coefficients (ICC) for index/summary scores. RESULTS: The average age of caregivers was 49.2 years, and 62.7 years for care recipients. Dyads most commonly consisted of spouses/partners (34.5%); 68.3% lived together. Proxy-CB aligned more closely with caregiver's view, with moderate to substantial agreement across CB domains (from κ = 0.48 for emotional to κ = 0.66 for financial). In the same perspective, the CarerQol-7D Index showed moderate agreement (ICC = 0.58) and the summary score of CB items substantial agreement (ICC = 0.76). Care recipients generally overestimated  CB in the Proxy-CB perspective, while they underestimated it in the CR-SPB perspective. CONCLUSION: Results demonstrate there is a difference between perspectives. Strong agreement in Proxy-CB perspective suggests that care recipients can potentially substitute for caregivers depending on the domain. CR-SPB agrees less with caregivers and may provide complementary information.

What matters most to people with metastatic uveal melanoma? A qualitative study to inform future measurement of health-related quality of life.

Metastatic uveal melanoma (mUM) is a rare cancer with poor prognosis, but novel treatments are emerging. Currently, there are no mUM-specific health-related quality of life (HRQL) questionnaires available for clinical research. We aimed to explore how mUM and its treatment affect HRQL and assess the content validity of existing questionnaires. Participants were patients with mUM and healthcare professionals involved in their care. Qualitative data were collected using semi-structured interviews and focus groups. Data collection and analysis used an integrative approach involving inductive questions/coding to elicit new concepts and deductive questions/coding based on domains of existing HRQL questionnaires. Initial interviews/focus groups focussed on HRQL questionnaires designed for patients with uveal melanoma or liver metastases. As new concepts were elicited, domains and items from other questionnaires were subsequently added. Seventeen patients and 16 clinicians participated. HRQL concerns assessed by uveal melanoma-specific questionnaires were largely resolved by the time of metastasis. The Functional Assessment of Cancer Therapy - Immunotherapy Module (FACT-ICM) adequately captured most immunotherapy-related side effects during initial treatment cycles. However, most patients emphasised emotional impacts over physical ones, focussing on the existential threat posed by disease amidst uncertainty about treatment accessibility and effectiveness. Patients were also concerned with treatment burden, including time commitment, travel, need for hospitalisation, and expenses. The relative importance of HRQL issues varied over time and across treatment modalities, with no single questionnaire being sufficient. Pending further development and psychometric testing, clinical researchers may need to take a modular approach to measuring the HRQL impacts of mUM.

Exploring the measurement of health related quality of life and broader instruments: A dimensionality analysis.

BACKGROUND: Comprehensively measuring the outcomes of interventions and policy programmes impacting both health and broader areas of quality of life (QoL) is important for decision-making within and across sectors. Increasingly, broad QoL measures are being developed to capture outcomes beyond health-related quality of life (HRQoL). Jointly exploring the dimensionality of diverse instruments can improve our understanding about their evaluative space and how they conceptually build on each other. This study explored the measurement relationship between five broader QoL measures and the most widely used HRQoL measure, the EQ-5D. METHODS: Participants from the Dutch general population (n = 1002) completed six instruments (n = 126 items) in December of 2020. The measurement relationship was explored using qualitative and quantitative dimensionality assessment methods. This included a content analysis and exploratory factor analyses which were used to develop a confirmatory factor model of the broader QoL dimensions. Correlations between the identified dimensions and self-reported overall health and wellbeing were also explored. RESULTS: The final CFA model exhibited acceptable/good fit and described 12 QoL dimensions: 'psychological symptoms', 'social relations', 'physical functioning', 'emotional resilience', 'pain', 'cognition', 'financial needs', 'discrimination', 'outlook on life/growth', 'access to public services', 'living environment', and 'control over life'. All dimensions were positively correlated to self-reported health and wellbeing, but the magnitudes in associations varied considerably (e.g., 'pain' had the strongest correlation with overall health but a weak correlation with wellbeing). CONCLUSIONS: This study contributes to a broader understanding of QoL by exploring the dimensionality and relationships among various QoL measures. A number of the dimensions identified are HRQoL-focused, with others covering broader constructs. Our findings offer insights for the development of comprehensive instruments, or use of instrument suites that capture multidimensional aspects of QoL. Further research should explore the relevance and feasibility/appropriateness of measuring the identified dimensions in different settings and populations.

Psychometric Properties of the EQ-5D-Y-5L for Children With Intellectual Disability.

OBJECTIVES: The EQ-5D-Y-5L is a generic preference-based measure of health-related quality of life for children. This study aimed to describe the distributional properties, test-retest reliability, and convergent validity of the EQ-5D-Y-5L in children with intellectual disability (ID). METHODS: Caregivers of children with ID (aged 4 to 18 years) completed an online survey, including a proxy-report EQ-5D-Y-5L, the Quality-of-life Inventory-Disability, and disability-appropriate measures corresponding to the EQ-5D dimensions: mobility, self-care (SC), usual activities (UA), pain/discomfort (PD), and worry/sadness/unhappiness. Twenty-one participants repeated the EQ-5D-Y-5L a few weeks later. Test-retest reliability was computed using weighted kappa and intraclass correlation coefficients, and convergent validity using Spearman's and Pearson's correlation coefficients. RESULTS: Caregivers of 234 children completed the survey, with <1% missing values. Only 1.7% reported "no problems" on all dimensions (11111). The dimensions with the lowest percentage of "no problems" were SC and UA (both 8%). Test-retest reliability coefficients were fair to substantial for 4 dimensions (weighted kappa .30 to .79) but low for PD and overall health, as measured by the visual analog scale (EQ-VAS). Convergent validity was strong (Spearman's correlation .65 to .87) for mobility, SC, and PD; moderate to strong for worry/sadness/unhappiness (.47 to .60) and the EQ-VAS (Pearson's correlation .49); and weak to moderate for UA (.21 to .52). CONCLUSIONS: Convergent validity was generally good; test-retest reliability varied. Children with ID had lower scores on SC and UA than other populations, and their EQ-VAS could fluctuate greatly, indicating poorer and less stable health-related quality of life.

The Ceiling Effects of EQ-5D-3L and 5L in General Population Health Surveys: A Systematic Review and Meta-Analysis.

OBJECTIVES: This review aims to examine the ceiling effects of EQ-5D-3L (3L) and EQ-5D-5L (5L) in general adult populations and identify the factors influencing these effects. METHODS: We searched 8 databases for observational studies published in English from inception to 24 July 2023. Ceiling effects were calculated by dividing the number of participants reporting full health at dimension or profile level by the total sample size. Subgroup analysis and meta-regression using the metafor package in R software were performed. RESULTS: We identified 94 studies from 70 articles, including 4 543 647 adults across 37 countries. The global pooled proportion of individuals reporting full health ("11111") was 56% (95% CI 51%-62%) for 3L and 49% (95% CI 44%-54%) for 5L. The self-care dimension showed the highest ceiling effects (3L: 97%; 5L: 94%), whereas pain/discomfort had the lowest (3L: 69%; 5L: 60%). The ceiling effects in East/South-East Asia were higher than in Europe by 25% (95% CI 18%-32%) in 3L and 9% (95% CI -2%-20%) in 5L. Adjusting for mean age and proportion of males, significant regional differences persisted in the overall profile level of 3L, in all 3L dimensions (except for self-care), and 5L dimensions (except for pain/discomfort and anxiety/depression). CONCLUSIONS: This review highlights significant ceiling effects in the EQ-5D, especially in Asian populations. The 5L version exhibited fewer ceiling effects than the 3L, indicating its superiority for general population surveys. Further research is crucial to understand the disparities in self-reported health outcomes between Asians and other populations.