Paul Kind

Development and preliminary testing of the new five-level version of EQ-5D (EQ-5D-5L)

PurposeThis article introduces the new 5-level EQ-5D (EQ-5D-5L) health status measure.MethodsEQ-5D currently measures health using three levels of severity in five dimensions. A EuroQol Group task force was established to find ways of improving the instrument’s sensitivity and reducing ceiling effects by increasing the number of severity levels. The study was performed in the United Kingdom and Spain. Severity labels for 5 levels in each dimension were identified using response scaling. Focus groups were used to investigate the face and content validity of the new versions, including hypothetical health states generated from those versions.ResultsSelecting labels at approximately the 25th, 50th, and 75th centiles produced two alternative 5-level versions. Focus group work showed a slight preference for the wording ‘slight-moderate-severe’ problems, with anchors of ‘no problems’ and ‘unable to do’ in the EQ-5D functional dimensions. Similar wording was used in the Pain/Discomfort and Anxiety/Depression dimensions. Hypothetical health states were well understood though participants stressed the need for the internal coherence of health states.ConclusionsA 5-level version of the EQ-5D has been developed by the EuroQol Group. Further testing is required to determine whether the new version improves sensitivity and reduces ceiling effects.

The time trade-off method: Results from a general population study

An important consideration when establishing priorities in health care is the likely effects that alternative allocations of resources will have on health-related quality-of-life (HRQoL). This paper reports on a large-scale national study that elicited the relative valuations attached by the general public to different states of health (defined in HRQoL terms). Health state valuations were derived using the time trade-off (TTO) method. The data from 3395 respondents were highly consistent, suggesting that it is feasible to use the TTO method to elicit valuations from the general public. The paper shows that valuations for severe health states appear to be affected by the age and the sex of the respondent; those aged 18-59 have higher valuations than those aged 60 or over and men have higher valuations than women. These results contradict those reported elsewhere and suggest that the small samples used in other studies may be concealing real differences that exist between population sub-groups. This has important implications for public policy decisions.

Testing the validity of the Euroqol and comparing it with the SF-36 health survey questionnaire

There is an interest in the consequences of deriving a single index measure of health for validity and sensitivity. This paper presents the results of testing a recent example of a general health measure designed to derive a single index, the Euroqol (EQ), and presents a comparison with a new, influential profile measure, the Short Form 36 (SF-36) Health Survey Instrument. The EQ and an anglicised version of the SF-36 health survey, both designed for self-completion, were included in a postal survey of a random sample of 1980 patients from two practice lists in Sheffield, UK. The response rate for the EQ questionnaire was 83%, and the rate of completion over 95%. Evidence was found for the construct validity of the EQ dimension responses and the derived total EQ health score in terms of distinguishing between groups with expected health differences. Considerable agreement was found between EQ responses and the total EQ score, and the UK SF-36 profile scores. There was substantial evidence of EQ being less sensitive at the ceiling (i.e. low levels of perceived ill-health) and throughout the range of health states. A recent restructuring of the EQ, may help overcome some of the problems with the physical dimensions by reducing their skewness.

US norms for six generic health-related quality-of-life indexes from the National Health Measurement study.

Background:A number of indexes measuring self-reported generic health-related quality-of-life (HRQoL) using preference-weighted scoring are used widely in population surveys and clinical studies in the United States. Objective:To obtain age-by-gender norms for older adults on 6 generic HRQoL indexes in a cross-sectional US population survey and compare age-related trends in HRQoL. Methods:The EuroQol EQ-5D, Health Utilities Index Mark 2, Health Utilities Index Mark 3, SF-36v2™ (used to compute SF-6D), Quality of Well-being Scale self-administered form, and Health and Activities Limitations index were administered via telephone interview to each respondent in a national survey sample of 3844 noninstitutionalized adults age 35–89. Persons age 65–89 and telephone exchanges with high percentages of African Americans were oversampled. Age-by-gender means were computed using sampling and poststratification weights to adjust results to the US adult population. Results:The 6 indexes exhibit similar patterns of age-related HRQoL by gender; however, means differ significantly across indexes. Females report slightly lower HRQoL than do males across all age groups. HRQoL seems somewhat higher for persons age 65–74 compared with people in the next younger age decade, as measured by all indexes. Conclusions:Six HRQoL measures show similar but not identical trends in population norms for older US adults. Results reported here provide reference values for 6 self-reported HRQoL indexes.

A Comparison of United Kingdom and Spanish General Population Time Trade-off Values for EQ-5D Health States:

Few studies have compared preference values for health states obtained in different countries. The present study compared Spanish and United Kingdom (UK) time trade-off values for EuroQol-5D health states. The same preference elicitation protocol was followed in both countries. Differences in values for 43 health states rated directly were analyzed using t tests, and regression coefficients generated by random effects modeling were compared by aggregating the 2 value sets and using dummy variables to analyze country effect by dimension and level of severity. For the milder health states, Spanish and UK value assignation was similar; for intermediate health states, Spanish values were both higher and lower than UK values, whereas for health states worse than death, UK values were generally higher than Spanish values. There were statistically significant differences (P < 0.01) in values for 34.9% of health states rated directly, and some preference reversals between countries. UK raters ascribed greater importance to dimensions of pain/discomfort and anxiety/depression, whereas Spanish raters placed more importance on functional dimensions of mobility and self-care. Further analysis is required to determine how these differences affect cost-effectiveness and cost-utility analyses.

Development of the EQ-5D-Y: a child-friendly version of the EQ-5D

PurposeTo develop a self-report version of the EQ-5D for younger respondents, named the EQ-5D-Y (Youth); to test its comprehensibility for children and adolescents and to compare results obtained using the standard adult EQ-5D and the EQ-5D-Y.MethodsAn international task force revised the content of EQ-5D and wording to ensure relevance and clarity for young respondents. Children’s and adolescents’ understanding of the EQ-5D-Y was tested in cognitive interviews after the instrument was translated into German, Italian, Spanish and Swedish. Differences between the EQ-5D and the EQ-5D-Y regarding frequencies of reported problems were investigated in Germany, Spain and South Africa.ResultsThe content of the EQ-5D dimensions proved to be appropriate for the measurement of HRQOL in young respondents. The wording of the questionnaire had to be adapted which led to small changes in the meaning of some items and answer options. The adapted EQ-5D-Y was satisfactorily understood by children and adolescents in different countries. It was better accepted and proved more feasible than the EQ-5D. The administration of the EQ-5D and of the EQ-5D-Y causes differences in frequencies of reported problems.ConclusionsThe newly developed EQ-5D-Y is a useful tool to measure HRQOL in young people in an age-appropriate manner.

Health state valuations from the general public using the Visual Analogue Scale

In the clinical and economic evaluation of health care, the value of benefit gained should be determined from a public perspective. The objective of this study was to establish relative valuations attached to different health states to form the basis for a ‘social tariff’ for use in quantifying patient benefit from health care. Three thousand three hundred and ninety-five interviews were conducted with a representative sample of the adult British population. Using the EuroQol health state classification and a visual analogue scale (VAS), each respondent valued 15 health states producing, in total, direct valuations for 45 states. Two hundred and twenty-one re-interviews were conducted approximately 10 weeks later. A near complete, and logically consistent, VAS data set was generated with good test-retest reliability (mean ICC=0.78). Both social class and education had a significant effect, where higher median valuations were given by respondents in social classes III–V and by those with intermediate or no educational qualifications. These effects were particularly noticeable for more severe states. The use of such valuations in a social tariff raises important issues regarding the use of the VAS method itself to elicit valuations for hypothetical health states, the production of separate tariffs according to social class and/or education and the appropriate measure of central tendency.

Valuations of EQ-5D health states: are the United States and United Kingdom different?

Purpose:We sought to compare directly elicited valuations for EQ-5D health states between the US and UK general adult populations. Methods:We analyzed data from 2 EQ-5D valuation studies where, using similar time trade-off protocols, values for 42 common health states were elicited from representative samples of the US and UK general adult populations. First, US and UK population mean valuations were estimated and compared for each health state. Second, random-effect models were used to compare the US and UK valuations while adjusting for known predictors of EQ-5D valuations (ie, age, sex, health state descriptors) and to investigate whether and how the valuations differ. Results:Population mean valuations of the 42 health states ranged from −0.38 to 0.88 for the United States and from −0.54 to 0.88 for the United Kingdom, with the US mean scores being numerically higher than the UK for 39 health states (mean difference: 0.11; range: −0.01 to 0.25). After adjusting for the main effects of known predictors, the average difference in valuations was 0.10 (P < 0.001). The magnitude of the difference in the US and UK valuations was not constant across EQ-5D health states; greater differences in valuations were present in health states characterized by extreme problems. Conclusions:Meaningful differences exist in directly elicited TTO valuations of EQ-5D health states between the US and UK general populations. Therefore, EQ-5D index scores generated using valuations from the US general population should be used for studies aiming to reflect health state preferences of the US general public.

South Korean time trade-off values for EQ-5D health states: modeling with observed values for 101 health states.

OBJECTIVES This study establishes the South Korean population-based preference weights for EQ-5D based on values elicited from a representative national sample using the time trade-off (TTO) method. METHODS The data for this paper came from a South Korean EQ-5D valuation study where 1307 representative respondents were invited to participate and a total of 101 health states defined by the EQ-5D descriptive system were directly valued. Both aggregate and individual level modeling were conducted to generate values for all 243 health states defined by EQ-5D. Various regression techniques and model specifications were also examined in order to produce the best fit model. Final model selection was based on minimizing the difference between the observed and estimated value for each health state. RESULTS The N3 model yielded the best fit for the observed TTO value at the aggregate level. It had a mean absolute error of 0.029 and only 15 predictions out of 101 had errors exceeding 0.05 in absolute magnitude. CONCLUSIONS The study successfully establishes South Korean population-based preference weights for the EQ-5D. The value set derived here is based on a representative population sample, limiting the interpolation space and possessing better model performance. Thus, this EQ-5D value set should be given preference for use with the South Korean population.

Measuring population health: A comparison of three generic health status measures

Objectives. The relative performance of three widely used generic health status measures (EQ-5D, a modified HUI3 [mHUI3], and SF-12) was compared within a general population sample. Materials and methods. Data were taken from a cohort of persons identified from the patient list of a large general practice in York, UK. Two-way comparisons were made between EQ-5D and mHUI3 and EQ-5D and SF-12. The measures were assessed in terms of their practical viability, coverage, and discrimination. Practical viability was evaluated in terms of the extent of missing responses and the proportion indicating difficulty with a measure. Coverage examined the range of responses across the items in the measures. Discrimination examined the capacity of the measures to discriminate between persons according to their self-reported morbidity and socioeconomic status. Results. One thousand one hundred twenty-six persons completed a postal questionnaire containing EQ-5D and either mHUI3 (n = 593) or SF-12 (n = 533). Missing responses were low across all three instruments. SF-12 showed a broad distribution of responses across its items however, responses on the mHUI3 hearing, speech and dexterity dimensions and the EQ-5D self-care dimension were highly skewed, with few persons reporting problems. In terms of summary scores, mHUI3 identified more mild health states than EQ-5D. EQ-5D and mHUI3 showed slightly better discrimination than SF-12. Conclusions. Despite the inherent differences in their descriptive systems and scoring functions, no one instrument performed better or worse than the other with respect to the criteria applied in this study. Some of the issues to be considered when choosing a population health measure are discussed.