Socioeconomic inequalities in patient-reported outcome measures of Dutch primary hip and knee arthroplasty patients for osteoarthritis.

OBJECTIVE: To study socio-economic inequalities in patient-reported outcomes in primary hip and knee arthroplasty (THA/TKA) patients for osteoarthritis, using two analytical techniques. METHODS: We obtained data from 44,732 THA and 30,756 TKA patients with preoperative and 12-month follow-up PROMs between 2014 and 2020 from the Dutch Arthroplasty Registry. A deprivation indicator based on neighborhood income, unemployment rate, and education level was linked and categorized into quintiles. The primary outcome measures were the EQ-5D-3L index and Oxford Hip/Knee Score (OHS/OKS) preoperative, at 12-month follow-up, and the calculated change score between these measurements. We contrasted the most and least deprived quintiles using multivariable linear regression, adjusting for patient characteristics. Concurrently, we calculated concentration indices as a non-arbitrary tool to quantify inequalities. RESULTS: Compared to the least deprived, the most deprived THA patients had poorer preoperative (EQ-5D -0.03 (95%CI -0.02, -0.04), OHS -1.26 (-0.99, -1.52)) and 12-month follow-up health (EQ-5D -0.02 (-0.01, -0.02), OHS -0.42 (-0.19, -0.65)), yet higher mean change (EQ-5D 0.02 (0.01, 0.03), OHS 0.84 (0.52, 1.16)). The most deprived TKA patients had similar results. The higher mean change among the deprived resulted from lower preoperative health in this group (confounding). After accounting for this, the most deprived patients had a lower mean change. The concentration indices showed similar inequality effects and provided information on the magnitude of inequalities over the entire socio-economic range. CONCLUSION: The most deprived THA and TKA patients have worse preoperative health, which persisted after surgery. The concentration indices allow comparison of inequalities across different outcomes (e.g., revision risk).

Evaluating Health Inequality in Five Caribbean Basin Countries Using EQ-5D-5L.

BACKGROUND: EQ-5D-5L is a standardized health outcomes instrument that can be added to national surveys to measure inequality in health outcomes. The aim of this study was to produce baseline values of health inequality using EQ-5D-5L for five countries in the Caribbean Basin region based on national surveys in 2012-2014. METHODS: The EQ-5D-5L questionnaire was included in adult population surveys of Barbados, Belize, Colombia, Jamaica and Trinidad and Tobago. EQ-5D-5L measures were calculated for demographic groups using stratifiers from the World Health Organization's PROGRESS-Plus framework, and generalized linear models were used to test for association between EQ-5D-5L and the PROGRESS-Plus variables. Ordered logit models were used to obtain odds ratios for the effect of the PROGRESS-Plus variables on reporting problems on the EQ-5D-5L dimensions. The Kakwani index was calculated for each country. RESULTS: Data were obtained for representative samples in each country, giving a combined total of 11,284 respondents. Different patterns of inequality were observed among the five countries. The biggest drivers of inequality were age and gender, and the biggest EQ-5D factors were self-care in Belize and pain/discomfort in the other four countries. CONCLUSION: This study demonstrated that the EQ-5D-5L instrument can easily be added to national surveys. Inequality measures from this study can be used as baseline values for comparisons with future similar surveys in these five countries to infer changes in health inequality as measured by EQ-5D outcomes. These can be used to track the performance of policy initiatives aimed at specific demographic groups.

Exploration of the Reasons Why Health State Valuation Differs for Children Compared With Adults: A Mixed Methods Approach.

OBJECTIVES: Evidence comparing utilities for adults and children consistently report higher utility values for child health states. This study investigates the reasons why child health states are valued differently. METHODS: A total of 80 respondents (United Kingdom, Belgium, The Netherlands) participated in 1.5-hour face-to-face interviews. Respondents valued 4 health states from 2 perspectives (8-year-old child, 40-year-old adult) using visual analog scale and time trade-off. A total of 32 respondents participated in think-aloud interviews. Audio recordings were analyzed by 2 independent coders using NVIVO software. Statements, nodes, and themes were reviewed cyclically until consensus was reached. RESULTS: Qualitative results: a total of 5 themes were identified in the data regarding child and adult valuation-intergenerational responsibility and dependency (childhood is crucial for forming life skills based on new experiences; adulthood is an important time to take care of the family), staying alive is important (life is worth living even with impaired health-related quality of life (HRQoL), for children and adults), awareness of poor HRQoL and ability to make decisions (children have difficulties comprehending poor HRQoL and their parents make their healthcare decision; adults can assess their own HRQoL and decide for themselves), coping ability (children are flexible and resilient; adults have experience with dealing with difficulties), and practical organization of care (children are cared for by their parents; adults are able to organize and pay for care). Mixed methods: comparing qualitative statements with respondents' higher utilities for child health states confirmed concordance between results. CONCLUSIONS: Quality-adjusted life-years are interpreted differently for children and adults. Child-specific value sets are needed to reflect society's preferences and to adequately conduct health technology assessment of pediatric treatments.

Health-related quality of life in patients with lower limb amputation - an assessment of the measurement properties of EQ-5D-3L and EQ-5D-5L using data from the Swedish Amputation and Prosthetics Registry.

PURPOSE: To assess the measurement properties of EQ-5D-3L and EQ-5D-5L in patients with a major lower limb amputation (LLA). METHODS: This was a retrospective register-based study using data from the Swedish Amputation and Prosthetics Registry (SwedeAmp). Patients with a six-months follow-up (including either EQ-5D-3L or EQ-5D-5L) after a major unilateral LLA were included. The measurement properties of EQ-5D-3L and EQ-5D-5L were compared in terms of feasibility, response patterns, informativity, and convergent and known-group validity. RESULTS: The sample included 700 patients with below-knee amputation (76%), above-knee amputation (18%), or knee disarticulation (7%). Responses to EQ-5D-3L and -5L were similar regarding feasibility (98% completion rate) and the proportion reporting no problems (7% and 6%). Compared to EQ-5D-3L, EQ-5D-5L showed higher absolute and relative informativity in all dimensions, with the largest improvement in the mobility dimension. In the analyses of convergent validity, the EQ-5D-5L generally showed stronger correlations with disease-specific measures. Only EQ-5D-5L was able to discriminate between subgroups with different amputation levels. CONCLUSION: The findings support the use of EQ-5D-5L over EQ-5D-3L in patients with an LLA, mainly due to improved informativity and improved convergent and known-group validity.Implications for rehabilitationThe measurement properties of two EQ-5D versions, EQ-5D-3L and EQ-5D-5L, has so far not been evaluated in patients with a lower limb amputation (LLA)The results support the use of EQ-5D-5L over the use of EQ-5D-3L, mainly due to improved informativity and stronger correlations with disease-specific patient-reported outcome measuresThe five-level version of EQ-5D is recommended for future applications of EQ-5D in clinical outcome studies, health economic evaluations, and in the routine follow-up of patients with a major LLAIn the early rehabilitation process six months after an LLA, the majority of patients reported problems with mobility, pain/discomfort, and usual activities.

Socio-demographic indicators of self-reported health based on EQ-5D-3L: A cross-country analysis of population surveys from 18 countries.

Background: Generic health-related quality of life instruments, such as the EQ-5D, are increasingly used by countries to monitor population health via general population health surveys. Our aim was to demonstrate analytic options to measure socio-demographic differences in self-reported health using the EuroQol Group's archive of EQ-5D-3L population surveys that accumulated over the past two decades. Methods: Analyses captured self-reported EQ-5D-3L data on over 100,000 individuals from 18 countries with nationally representative population surveys. Socio-demographic indicators employed were age, sex, educational level and income. Logistic regression odds ratios and the health concentration index methodology were used in the socio-demographic analysis of EQ-5D-3L data. Results: Statistically significant socio-demographic differences existed in all countries (p < 0.01) with the EQ VAS based health concentration index varying from 0.090 to 0.157 across countries. Age had generally the largest contributing share, while educational level also had a consistent role in explaining lower levels of self-reported health. Further analysis in a subset of 7 countries with income data showed that, beyond educational level, income itself had an additional significant impact on self-reported health. Among the 5 dimensions of the EQ-5D-3L descriptive system, problems with usual activities and pain/discomfort had the largest contribution to the concentration of overall self-assessed health measured on the EQ VAS in most countries. Conclusion: The EQ-5D-3L was shown to be a powerful multi-dimensional instrument in the analyses of socio-demographic differences in self-reported health using various analytic methods. It offered a unique insight of inequalities by health dimensions.

General population normative data for the EQ-5D-3L in the five largest European economies.

AIM: The EQ-5D is a generic measure of health that is widely applied for health economic and non-economic purposes. Population norms can be used to facilitate the interpretation of EQ-5D data. The objective of this study was to develop a set of pooled normative EQ-5D-3L values for the five largest European economies (EUR5). METHODS: EQ-5D-3L index values based on the time trade-off (TTO) were available for all EUR5 countries (n = 21,425): France, Germany, Italy, Spain, and the United Kingdom (UK). Country-specific data sets were aggregated and weighted to facilitate the derivation of norms for gender and age groups. Analyses included equal weighting and weighting by population and economy size. Norms were also calculated using the European visual analog scale-based value set (European VAS), the EQ VAS and separately by dimension. RESULTS: Pooled mean (SD) population weighted TTO values for males/females were 0.967 (0.122)/0.959 (0.118) for ages 18-24; 0.965 (0.096)/0.954 (0.117) for ages 25-34; 0.943 (0.165)/0.936 (0.169) for ages 35-44; 0.934 (0.150)/0.921 (0.157) for ages 45-54; 0.896 (0.188)/0.875 (0.197) for ages 55-64; 0.900 (0.158)/0.839 (0.218) for ages 65-74; and 0.830 (0.234)/0.756 (0.291) for ages 75 and older. Mean values decreased and variance increased with age; females had slightly lower mean values than males across all age bands. The unequal weighting approaches produced similar point estimates with smaller variances. Mean values for the European VAS were slightly lower than those for the TTO-based index. DISCUSSION: Normative EQ-5D-3L values can be used to benchmark the outcomes of treated patients against the health of the general population. EUR5 norms may be useful in research applications inferring to Europe or the European Union as a whole, particularly when sample size precludes analysis at the country level.

Methods Used to Identify, Test, and Assess Impact on Preferences of Bolt-Ons: A Systematic Review.

OBJECTIVES: The question of whether additional dimensions should be added to the EQ-5D, so-called bolt-ons, has been researched since the 1990s. Several candidate bolt-ons have been tested. The aim of this systematic review was to provide an overview of EQ-5D bolt-on studies, including the origin of possible suitable bolt-ons, their format, and methods that were used to examine their value. METHODS: Studies were identified through database search and reference screening and assessed based on a set of inclusion criteria. All studies that investigated bolt-ons for the EQ-5D were eligible for inclusion. Two reviewers independently extracted information from all included studies on objectives, study design, EQ-5D version used, the investigated bolt-ons, methods used to achieve objectives, and outcomes. RESULTS: Of 308 initially identified studies, 28 studies met the inclusion criteria. Of these studies, 3 identified potentially suitable bolt-on dimensions, 13 investigated the psychometric performance of EQ-5D + bolt-on(s), and 6 investigated the impact of the bolt-on on health state preferences. In total, 26 bolt-ons were identified, of which cognition was the most frequently mentioned. A wide variety of bolt-on identification methods, psychometric performance tests, and health state valuation methods were used in the included studies. CONCLUSION: A range of bolt-on dimensions has been investigated using diverse methods. Guidelines are needed to standardize the wording of the bolt-on dimension and response options, evaluate minimal important gain of the bolt-on, and facilitate quality assessment of bolt-on studies. Subsequently, guidelines will facilitate decision making on whether or not to implement a bolt-on dimension to the EQ-5D.

A Head-to-Head Comparison of the Standard Quality-Adjusted Life Year Model With the Annual Profile Model.

OBJECTIVES: The standard quality-adjusted life year (QALY) model (SQM) assumes time-utility independence within constant health states and additive independence when health varies over time. The validity of SQM has been challenged through reported violations of these assumptions. An alternative approach that relaxes these assumptions is to assign a single valuation to an entire health profile: an integral assessment of disease severity over time. Here, we compare SQM with the annual profile model (APM) and test SQM for additive independence. METHODS: Eighty-two respondents valued 6 episodic conditions, including 4 of short duration, with SQM and APM, using the time trade-off method. Inter-rater reliability was assessed using intraclass correlation coefficients. Face validity was tested by asking respondents how well they were able to imagine the health states under SQM and APM. We calculated SQM QALY values for a 1-year time period, allowing for a direct comparison with APM values. For the short-term conditions we expected higher QALY values for SQM, violating additive independence. RESULTS: APM showed higher interrater reliability (intraclass correlation coefficient of 0.53 vs 0.18, respectively) and better face validity than SQM, with 6% (APM) vs 21% (SQM) of all respondents reporting difficulties. Additive independence of SQM was violated in 5 of the 6 conditions (including the 4 short duration health states), with higher QALY values under SQM (mean difference 0.04). CONCLUSION: The impact of short-term conditions is systematically underestimated under SQM when compared to a health profile model. APM is a less restrictive model and demonstrates better validity.

How to measure fluctuating impairments in people with MS: development of an ambulatory assessment version of the EQ-5D-5L in an exploratory study.

BACKGROUND: Health fluctuations even within a single day are typical in multiple sclerosis (MS), but are not captured by widely used questionnaires like the EQ-5D-5L. This exploratory study aimed to develop an ambulatory assessment (AA) version of the EQ-5D-5L (EQ-5D-AA) where patients rate their health on mobile phones multiple times per day over several days, and to assess its feasibility and face validity. METHODS: An initial EQ-5D-AA version was based on two patient focus groups. It was then tested and continuously developed in an iterative process: patients completed it over several days, followed by debriefing interviews. Findings were used to refine the EQ-5D-AA, with the resulting version being tested by the subsequent wave of patients until participants declared no need for changes anymore. Before and after the AA period, participants completed the standard paper-based EQ-5D-5L asking about 'today'. RESULTS: Focus group participants reported that their impairments often fluctuated between and within days. They regarded an AA with three assessments per day over seven days most appropriate; assessment should be retrospective to the previous assessment, but not all items should be assessed at each time point. Four waves of AA testing were conducted. Thirteen out of the 17 participants preferred the AA over standard assessment as they regarded it more informative, but not too burdensome. CONCLUSION: The newly developed one-week AA of the EQ-5D-5L captures within-day and day-to-day health fluctuations in people with MS. From the patients' perspective, it is a feasible and face valid way to provide important information beyond what is captured by the standard EQ-5D-5L.

EQ-5D-5L Population Norms and Health Inequality in Colombia.

OBJECTIVES: The EQ-5D-3L and EQ-5D-5L instruments have been used in studies of patient and demographic groups in Colombia, but to date there are no 5L population norms. This study aimed to produce a set of EQ-5D-5L population norms for Colombia and to see what insights into health inequality in Colombia can be discerned from these norms. METHODS: The EQ-5D-5L self-reported health questionnaire was included in a survey of a representative sample of 3400 adults aged 18 to 64 in Colombia. EQ-5D-5L states, mean EQ VAS, and index values were obtained by sex, age, education, income group, ethnicity, residence, employment status, health insurance status, and household size. EQ-5D-5L index values from Uruguay were used. Regression models were used to investigate inequality. RESULTS: The mean EQ VAS value was 85.3, the mean index value was 0.953, and 52.2% of the sample reported being in state 11111. Self-reported health was higher for men, declined in higher age groups, and was lower for lower-income and education groups. The EQ-5D-5L instrument was observed to be more sensitive than the EQ-5D-3L instrument in Colombia. The dimensions with the highest prevalence of reported problems were anxiety/depression and pain/discomfort. The main drivers of inequality were age, sex, income, and education. CONCLUSIONS: The population norms developed in this study can be used as baseline values for future studies of patient or treatment groups, and for investigations into the health of specific demographic groups.

A vision 'bolt-on' increases the responsiveness of EQ-5D: preliminary evidence from a study of cataract surgery.

OBJECTIVES: (1) To evaluate the effect of adding a vision dimension ('bolt-on') to the 5-level EQ-5D (EQ-5D-5L) and 3-level EQ-5D (EQ-5D-3L) on their responsiveness, and (2) to compare the responsiveness of a vision 'bolt-on' EQ-5D-3L (EQ-5D-3L + V) with SF-6D and Health Utilities Index Mark 3 (HUI3) to the benefit of cataract surgery. METHODS: Sixty-three patients were assessed before and after their cataract surgery using the EQ-5D-3L, EQ-5D-5L, SF-6D, HUI3, as well as a 3-level and a 5-level vision dimension. Preference-based indices were calculated using available value sets for EQ-5D-3L, EQ-5D-3L + V, EQ-5D-5L, SF-6D, and HUI3, and non-preference-based indices were calculated using the sum-score method for EQ-5D-5L and EQ-5D-5L + V (vision bolt-on EQ-5D-5L). Responsiveness was assessed using the standardized response mean (SRM) and F-statistic. RESULTS: Among preference-based indices, mean changes from pre to post-surgery in EQ-5D-3L + V and EQ-5D-3L indices were 0.031 and 0.018, respectively. The mean changes for EQ-5D-5L, SF-6D and HUI3 indices were 0.020, 0.012 and 0.105, respectively. The SRM (F-statistic) for EQ-5D-3L + V and EQ-5D-3L indices were 0.458 (13.2) and 0.098 (0.6), respectively. The responsiveness of EQ-5D-3L + V was better than EQ-5D-5L, SF-6D; the responsiveness of HUI3 was better than all other measures. Using non-preference-based indices, mean change for EQ-5D-5L + V and EQ-5D-5L were 0.067 and 0.017, respectively. The corresponding SRM (F-statistic) were 0.709 (31.7) and 0.295 (5.4). CONCLUSIONS: Preliminary evidence from our study suggests that a vision 'bolt-on' may increase the responsiveness of EQ-5D-3L and EQ-5D-5L to change in health outcomes experienced by patients undergoing cataract surgery. In absence of the preference-based vision bolt-on EQ-5D-5L index, HUI3 was the most responsive measure.

EQ-5D-5L population norms and health inequalities for Trinidad and Tobago.

The EQ-5D instrument is now used in many health systems as a health outcomes measure. Recently an EQ-5D valuation study was conducted for Trinidad and Tobago, but thus far there have been no population norms published for Trinidad and Tobago or for any Caribbean country. The objective of this study is to provide a set of population norms, and to investigate inequalities in health in Trinidad and Tobago. The EQ-5D-5L questionnaire was included in the 2012/2013 Adult Population Survey of the Global Entrepreneurship Monitor for Trinidad and Tobago. This survey covered a representative sample of 2,036 adults aged 18 and over. Demographic data and self-reported health using EQ-5D-5L were collected. The Trinidad and Tobago value set was used to obtain EQ-5D index values. The Kakwani index and logistic regression models were used to evaluate inequalities in health. Mean EQ-5D index values and EQ-VAS values were calculated by age group, ethnicity, gender, income, educational attainment, employment status and place of residence. The 10 most commonly observed EQ-5D-5L states accounted for 90% of the respondents. The mean VAS value for the sample was 83.6 and the mean EQ-5D-5L index value was 0.95. Pain/discomfort was found to be the EQ-5D dimension with the highest prevalence of reported problems with 22% of the population reporting pain at any level. Self-care was the dimension with the lowest prevalence of problems reported at any level (3%). Health declines with increasing age, and men reported fewer problems and higher levels of self-reported health than women. Age, gender and education level were found to be important drivers of health status as measured by the EQ-5D instrument. Being in a very low income group was also observed to affect EQ-VAS values among younger respondents. The population norms provided in this study can be used by clinicians, academics and policy makers in several ways. They can be used in comparing different demographic groups or patient groups, or as a basis for tracking the progress of patients through a treatment regimen. They can also provide a baseline for cost utility analysis of health interventions for Trinidad and Tobago.

Health-related quality of life in injury patients: the added value of extending the EQ-5D-3L with a cognitive dimension.

INTRODUCTION: The EQ-5D is frequently used to understand the development of health-related quality of life (HRQL) following injury. However, the lack of a cognition dimension is generally felt as disadvantageous as many injuries involve cognitive effects. We aimed to assess the added value of a cognitive dimension in a cohort of injury patients. METHODS: We analyzed EQ-5D-3L extended with cognition (EQ-5D + C) dimension responses of 5346 adult injury patients. We studied dimension dependency, assessed the additional effect of the cognitive dimension on the EQ-VAS, and, using the EQ-VAS as a dependent variable, determined the impact of EQ-5D and EQ-5D + C attributes in multivariate regression analyses. RESULTS: Extreme cognitive problems combined with no problems on other dimensions are uncommon, whereas severe problems on other dimensions frequently occur without cognitive problems. The EQ-VAS significantly decreased when cognitive problems emerged. Univariate regression analyses indicated that all EQ-5D + C dimensions were significantly associated with the EQ-VAS. Exploratory analyses showed that using any set of five of the six EQ-5D + C dimensions resulted in almost identical explained variance, and adding the remaining 6th dimension resulted in a similar additional impact. CONCLUSIONS: The addition of the cognition dimension increased the explanatory power of the EQ-5D-3L. Although the increase in explanatory power was relatively small after the cognition dimension was added, the decrease of HRQoL (measured with the EQ-VAS) resulting from cognitive problems was comparable to the decreases resulting from other EQ-5D dimensions.

EQ-5D-5L is More Responsive than EQ-5D-3L to Treatment Benefit of Cataract Surgery.

BACKGROUND: It is not clear whether 5-level EQ-5D (EQ-5D-5L) utilities based on recently developed value sets are more responsive than 3-level EQ-5D (EQ-5D-3L) utilities. OBJECTIVES: The study aims were to compare (1) the responsiveness of EQ-5D-5L and EQ-5D-3L utilities and (2) the responsiveness of these utilities with the Short Form-6 Dimension (SF-6D) and Health Utilities Index Mark 3 (HUI3) utilities to the treatment benefit of cataract surgery. METHODS: A total of 148 patients were interviewed before and after their cataract surgery using EQ-5D-3L, EQ-5D-5L, SF-6D, and HUI3. Responsiveness was assessed for all measures using the mean change (post-treatment-pre-treatment), standardized effect size (SES), standardized response mean (SRM), and F-statistic. RESULTS: Using the Singapore value sets, mean change for EQ-5D-3L and EQ-5D-5L utilities was 0.016 and 0.028, SES was 0.097 and 0.199; SRM was 0.091 and 0.196; and F-statistic was 1.2 and 5.7, respectively. Similar trends were observed using the UK/England EQ-5D value sets, although the magnitude was slightly smaller. The mean change, SES, SRM and F-statistics for SF-6D (UK value set) were 0.020, 0.234, 0.249, and 9.2, respectively. The values of mean change, SES, SRM and F-statistics for HUI3 (Canada value set) were 0.080, 0.472, 0.474, and 33.3, respectively. CONCLUSIONS: The EQ-5D-5L utilities tend to be more responsive than the EQ-5D-3L utilities to treatment benefits of cataract surgery. The HUI3 utilities are more responsive than both the EQ-5D-5L and SF-6D, and SF-6D utilities may be slightly more responsive than the EQ-5D-5L for assessing patients undergoing cataract surgery.

Assessment of Health-Related Quality of Life between People with Parkinson's Disease and Non-Parkinson's: Using Data Drawn from the '100 for Parkinson's' Smartphone-Based Prospective Study.

Background: This study aims to assess the specific difference of the health-related quality of life between people with Parkinson's and non-Parkinson's. Methods: A total of 1710 people were drawn from a prospective study with a smartphone-based survey named '100 for Parkinson's' to assess health-related quality of life. The EQ-5D-5L descriptive system and the EQ visual analogue scale were used to measure health-related quality of life and a linear mixed model was used to analyze the difference. Results: The mean difference of EQ-5D-5L index values between people with Parkinson's and non-Parkinson's was 0.15 (95%CI: 0.12, 0.18) at baseline; it changed to 0.17 (95%CI: 0.14, 0.20) at the end of study. The mean difference of EQ visual analogue scale scores between them increased from 10.18 (95%CI: 7.40, 12.96) to 12.19 (95%CI: 9.41, 14.97) from baseline to the end of study. Conclusion: Data can be captured from the participants' own smart devices and support the notion that health-related quality of life for people with Parkinson's is lower than non-Parkinson's. This analysis provides useful evidence for the EQ-5D instrument and is helpful for public health specialists and epidemiologists to assess the health needs of people with Parkinson's and indirectly improve their health status.

Is EQ-5D-5L Better Than EQ-5D-3L? A Head-to-Head Comparison of Descriptive Systems and Value Sets from Seven Countries.

OBJECTIVE: This study describes the first empirical head-to-head comparison of EQ-5D-3L (3L) and EQ-5D-5L (5L) value sets for multiple countries. METHODS: A large multinational dataset, including 3L and 5L data for eight patient groups and a student cohort, was used to compare 3L versus 5L value sets for Canada, China, England/UK (5L/3L, respectively), Japan, The Netherlands, South Korea and Spain. We used distributional analyses and two methods exploring discriminatory power: relative efficiency as assessed by the F statistic, and an area under the curve for the receiver-operating characteristics approach. Differences in outcomes were explored by separating descriptive system effects from valuation effects, and by exploring distributional location effects. RESULTS: In terms of distributional evenness, efficiency of scale use and the face validity of the resulting distributions, 5L was superior, leading to an increase in sensitivity and precision in health status measurement. When compared with 5L, 3L systematically overestimated health problems and consequently underestimated utilities. This led to bias, i.e. over- or underestimations of discriminatory power. CONCLUSION: We conclude that 5L provides more precise measurement at individual and group levels, both in terms of descriptive system data and utilities. The increased sensitivity and precision of 5L is likely to be generalisable to longitudinal studies, such as in intervention designs. Hence, we recommend the use of the 5L across applications, including economic evaluation, clinical and public health studies. The evaluative framework proved to be useful in assessing preference-based instruments and might be useful for future work in the development of descriptive systems or health classifications.

Valuing Health Using Time Trade-Off and Discrete Choice Experiment Methods: Does Dimension Order Impact on Health State Values?

BACKGROUND: Health states defined by multiattribute instruments such as the EuroQol five-dimensional questionnaire with five response levels (EQ-5D-5L) can be valued using time trade-off (TTO) or discrete choice experiment (DCE) methods. A key feature of the tasks is the order in which the health state dimensions are presented. Respondents may use various heuristics to complete the tasks, and therefore the order of the dimensions may impact on the importance assigned to particular states. OBJECTIVE: To assess the impact of different EQ-5D-5L dimension orders on health state values. METHODS: Preferences for EQ-5D-5L health states were elicited from a broadly representative sample of members of the UK general public. Respondents valued EQ-5D-5L health states using TTO and DCE methods across one of three dimension orderings via face-to-face computer-assisted personal interviews. Differences in mean values and the size of the health dimension coefficients across the arms were compared using difference testing and regression analyses. RESULTS: Descriptive analysis suggested some differences between the mean TTO health state values across the different dimension orderings, but these were not systematic. Regression analysis suggested that the magnitude of the dimension coefficients differs across the different dimension orderings (for both TTO and DCE), but there was no clear pattern. CONCLUSIONS: There is some evidence that the order in which the dimensions are presented impacts on the coefficients, which may impact on the health state values provided. The order of dimensions is a key consideration in the design of health state valuation studies.

Comparing the standard EQ-5D three-level system with a five-level version.

OBJECTIVES: The aim of this study is a head-to-head comparison of the performance of the three-level EQ-5D (3L) and a newly developed five-level version (5L). METHODS: Eighty-two respondents valued 15 standardized disease descriptions and their own health on three response scales (3L, 5L, and visual analog scale [VAS]) for all five EQ-5D dimensions. Performance was studied in terms of feasibility, face validity, redistribution properties, ordinality, convergent validity, discriminatory power, and test-retest and interobserver reliability. RESULTS: The majority of participants judged 5L as the preferred system in terms of feasibility (76%) and face validity (75%). In total, 1.1% of responses were inconsistent. Ordinality of 5L was confirmed in all cases. Convergent validity of 3L-VAS (range: 0.88-0.99) and 5L-VAS (0.90-0.99) were high and about equal. Discriminatory power (informativity) improves considerably with 5L without loss of Evenness. Interobserver reliability (0.49 vs. 0.57) and test-retest reliability (0.52 vs. 0.69) were higher in 5L. CONCLUSION: The EQ-5D five-level version appears a valid and reliable extension of the three-level system. The new 5L system is particularly useful for describing mild health problems and monitoring population health.

Feasibility and reliability of the annual profile method for deriving QALYs for short-term health conditions.

INTRODUCTION: When health varies over time, the standard quality-adjusted life year model operates under the assumptions of time utility independence within each health state and additive independence between health states. These assumptions can be relaxed by an integral assessment of disease severity over time. The authors present the annual profile method (APM), which values health profiles on a 1-year base, and test the APM for feasibility, consistency, and test-retest reliability. METHODS: A population panel, general practitioners, medical advisers, and a panel of the Dutch Consumers Association valued vignettes for 46 disease stages using the visual analog scale (VAS) and time tradeoff (TTO) methods. Vignettes contained disease-specific information, a generic description (EQ-6D5L), a description of the disease course over time, and a visual representation of the disease. Feasibility was tested by missing and inconsistent responses. Consistency between and within panels was tested with a generalizability study, analysis of variance, and standard correlation coefficients. Test-retest reliability was tested with a generalizability study and intra-class correlation coefficients. RESULTS: Missing and inconsistent responses were < 2.6%. The valuations were consistent across panels, with generalizability coefficients of 0.78 (VAS) and 0.64 (TTO). Within the main population panel, internal consistency was satisfactory and the influence of background characteristics negligible. Test-retest reliability was high, with generalizability coefficients of 0.90 (VAS) and 0.72 (TTO). CONCLUSION: Feasibility and reliability of the APM for realistic health profiles are good to excellent. The APM is a promising step to bridge the gap between the quality-adjusted life year methodology and clinical reality.

Evaluating the discriminatory power of EQ-5D, HUI2 and HUI3 in a US general population survey using Shannon's indices.

OBJECTIVES: To compare quantitatively the discriminatory power of the EQ-5D, HUI2 and HUI3 in terms of absolute and relative informativity, using Shannon's indices. METHODS: EQ-5D and HUI2/3 data completed by a sample of the general adult US population (N = 3,691) were used. Five dimensions allowed head-to-head comparison of informativity: Mobility/Ambulation; Anxiety/Depression/Emotion; Pain/Discomfort (EQ-5D; HUI2; HUI3); Self-Care (EQ-5D; HUI2); and Cognition (HUI2; HUI3). Shannon's index and Shannon's Evenness index were used to assess absolute and relative informativity, both by dimension and by instrument as a whole. RESULTS: Absolute informativity was highest for HUI3, with the largest differences in Pain/Discomfort and Cognition. Relative informativity was highest for EQ-5D, with the largest differences in Mobility/Ambulation and Anxiety/Depression/Emotion. Absolute informativity by instrument was consistently highest for HUI3 and lowest for EQ-5D, and relative informativity was highest for EQ-5D and lowest for HUI3. DISCUSSION: Performance in terms of absolute and relative informativity of the common dimensions of the three instruments varies over dimensions. Several dimensions are suboptimal: Pain/Discomfort (EQ-5D) seems too crude with only 3 levels, and the level descriptions of Ambulation (HUI3) and Self-Care (HUI2) could be improved. In absence of a formal measure, Shannon's indices provide useful measures for assessing discriminatory power of utility instruments.