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

Purpose

To 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.

Methods

An 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.

Results

The 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.

Conclusions

The newly developed EQ-5D-Y is a useful tool to measure HRQOL in young people in an age-appropriate manner.     

Comparing the psychometric properties of the EQ-5D-3L and EQ-5D-5L in cancer patients in Korea

Purpose

This study was conducted to assess the redistribution properties of the EQ-5D-3L when using the EQ-5D-5L and to compare the validity, informativity, and reliability of both EQ-5D-3L and EQ-5D-5L in Korean cancer patients.

Methods

Patients visiting one ambulatory cancer center self-administered the two versions of the EQ-5D and the EORTC QLQ-C30 questionnaire. Redistribution properties in each dimension of EQ-5D were analyzed between EQ-5D-3L and EQ-5D-5L. Informativity was evaluated using the Shannon entropy and ceiling effect. Convergent validity was evaluated by comparing the EQ-VAS, ECOG performance status, and EORTC QLQ-C30 subscales. Reliability was also evaluated in terms of test?Cretest reliability.

Results

All levels of the EQ-5D-3L substantially partitioned into associated levels of the EQ-5D-5L. The average inconsistency rate of the two versions was 3.5%. Absolute informativity was higher for the EQ-5D-5L than for the EQ-5D-3L, but their informative efficiency tended to be similar. The proportion of ??perfect health?? (11111) decreased from 16.8% in the EQ-5D-3L to 9.7% in the EQ-5D-5L. EQ-5D-5L demonstrated similar or higher correlations with the EQ-VAS, ECOG performance status, and EORTC QLQ-C30, than the EQ-5D-3L. The intraclass correlation coefficient of the EQ-5D-5L index was 0.77.

Conclusions

The EQ-5D-5L had greater informativity and lower rate in the ceiling effect than those values of the EQ-5D-3L. The EQ-5D-5L showed good construct validity and reasonable reliability. Therefore, considering these findings, the EQ-5D-5L may be preferable to the EQ-5D-3L.     

Translation and validation of non-English versions of the Ankylosing Spondylitis Quality of Life (ASQOL) questionnaire

Background

The EQ-5D is a reliable tool for measuring Health-Related Quality of Life (HRQoL). However, concern has been expressed that it may ignore elements of HRQoL, particularly cognition. In response to this concern, the EQ-5D has been extended with a cognitive dimension (EQ-5D+C). The aim of this study was to compare the performance of the EQ-5D and the EQ-5D+C in elderly patients with cognitive impairments by assessing their construct validity and responsiveness.

Methods

Data from the MEDICIE study (n = 196) were used, in which all questionnaires were rated by proxies.

Results

Regarding construct validity, we found similar correlations between the EQ-5D and the Mini Mental State Examination (MMSE) and between the EQ-5D+C and the MMSE. Furthermore, both the EQ-5D and the EQ-5D+C were responsive to changes in the MMSE, with the EQ-5D performing slightly better.

Conclusion

We conclude that the EQ-5D performs well for evaluating HRQoL in a population with cognitive impairments. Based on the results of this explorative study, it does not seem necessary to adjust the current classification system by adding a cognitive dimension. However, in order to compare both instruments regarding utility values, it is necessary to develop a new scoring algorithm for the EQ-5D+C by conducting a general population study. Considering the explorative nature of this study, it is recommended that more aspects of the validity of both the EQ-5D and the EQ-5D+C are explored in patients with cognitive impairments using a more tailored study design.     

Comparison of the Psychometric Properties of the EQ-5D-3L-Y and EQ-5D-5L-Y Instruments in Spanish Children and Adolescents

ObjectivesThe study aimed to assess the reliability and validity of EQ-5D-5L-Y and to compare the performance of EQ-5D-5L-Y with EQ-5D-3L-Y in children and adolescents.MethodsThe Spanish versions of the 3L and 5L of EQ-5D for youths, were administered to children and adolescents from the general population. Feasibility and reliability were determined for the EQ-5D-5L-Y. The EQ-5D-5L-Y and EQ-5D-3L-Y were evaluated in terms of ceiling effects, informativity, and correlations with other generic measurements of health-related quality of life.ResultsA total of 714 healthy children and adolescents (10.7 ± 2.1 years old) from the general population participated in the study. Most of the sample reported full health status. The feasibility and reliability for the EQ-5D-5L-Y were acceptable, but the questionnaire showed a low convergent validity. Absolute informativity (Shannon index) showed a slight increase in all dimensions of the 5L compared with the 3L; nevertheless, there were only statistically significant differences between 5L and 3L in the dimension “feeling worried, sad, or unhappy” and also on the overall system. Relative informativity (Shannon evenness index) showed a decrease in the 5L compared with 3L for all dimensions, except for “looking after myself.” Correlations with other health measurements, in both 3L and 5L, showed similar results to those observed in the international EQ-5D-3L-Y validation study.ConclusionThe results show that EQ-5D-5L-Y is feasible, consistent, and reliable, but there are minor differences in the ceiling effect and informativity between the EQ-5D-5L-Y and EQ-5D-3L-Y versions in the general population.     

Comparing the psychometric properties of the EQ-5D-3L and EQ-5D-5L descriptive systems and utilities in atopic dermatitis

Background

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder affecting up to 10% of adults. The EQ-5D is the most commonly used generic preference-accompanied measure to generate quality-adjusted life years (QALYs) for economic evaluations.

Objectives

We aimed to compare psychometric properties of the three-level and five-level EQ-5D (EQ-5D-3L and EQ-5D-5L) in adult patients with AD.

Methods

In a multicentre cross-sectional study, 218 AD patients with a broad range of severity completed the EQ-5D-3L, EQ-5D-5L, Dermatology Life Quality Index (DLQI) and Skindex-16. Disease severity outcomes included the Investigator Global Assessment, Eczema Area and Severity Index and the objective SCORing Atopic Dermatitis.

Results

A good agreement was established between the two EQ-5D versions with an intraclass correlation coefficient of 0.815 (95% CI 0.758–0.859, p < 0.001). Overall, 33 different health state profiles occurred in the EQ-5D-3L and 84 in the EQ-5D-5L. Compared to the EQ-5D-3L, ceiling effect was reduced for the mobility, self-care, usual activities and pain/discomfort dimensions by 4.6–11.5%. EQ-5D-5L showed higher average relative informativity (Shannon’s evenness index: 0.64 vs. 0.59). EQ-5D-5L demonstrated better convergent validity with EQ VAS, DLQI and Skindex-16. The two measures were similar in distinguishing between groups of patients based on disease severity and skin-specific quality of life with a moderate or large effect size (η² = 0.083–0.489).

Conclusion

Both instruments exhibited good psychometric properties in AD; however, the EQ-5D-5L was superior in terms of ceiling effects, informativity and convergent validity. We recommend the use of the EQ-5D-5L to measure health outcomes in clinical settings and for QALY calculations in AD.

     

A comparison of EQ-5D index scores derived from the US and UK population-based scoring functions.

The authors recently introduced a new preference-based scoring function for the EQ-5D (D1 model) based on time tradeoff valuations from the general adult US population: In this study, they compared the EQ-5D index scores derived from the US (D1) algorithm to the more familiar UK (N3) algorithm. They compared preference-based EQ-5D index scores for all possible EQ-5D health states and differences in EQ-5D index scores between pairs of EQ-5D health states predicted by the D1 and N3 models. The responsiveness of D1- and N3-predicted EQ-5D index scores was assessed using simulated transitions between EQ-5D health states. The mean (SD) EQ-5D index scores for all 243 health states predicted by the D1 and N3 models were 0.37 (0.23) and 0.14 (0.31), respectively. The mean (SD) absolute difference in EQ-5D index scores for all 29,403 pairs of health states was 0.25 (0.19) and 0.35 (0.27), according to the D1 and N3 models, respectively. The D1 and N3 models were consistent in predicting gains/losses for 27,592 (94%) transitions between EQ-5D health state pairs; Cohen effect size, calculated using these 27,592 consistent transitions, was 1.58 and 1.59 for the D1 and N3 models, respectively. Based on these simulation results, it appears that the D1 model would lead to smaller gains in quality-adjusted life years than the N3 model; however, their responsiveness appears to be similar. Empirical studies are needed to examine whether these 2 EQ-5D scoring functions would lead to different conclusions in cost-utility analyses.     

A comparison of individual and social time trade-off values for health states in the general population

This study aimed to compare directly elicited individual time trade-off (TTO) values in a general population sample with the social values derived using the UK EQ-5D index tariff. In the Stockholm County 1998 postal Public Health Survey (n=4950, 20-88 years), the EQ-5D self-classifier, a TTO and a rating scale (RS) question were included (n=2549 for all three questions). The mean TTO (EQ-5D) value was 0.943 (0.890) in the youngest age-group and 0.699 (0.733) in the oldest age-group. The difference between TTO and EQ-5D values was greater in more severe health status groups was. The same equation as for the UK EQ-5D index tariff was estimated for TTO and RS and resulted in significant and consistent coefficients for nearly all dimensions. The coefficients for moderate problems were closer to the EQ-5D index tariff than the coefficients for severe problems. Age was also significant after controlling for the EQ-5D dimensions (p<0.05). The results suggest that individual and social TTO values differ systematically and that the difference is greater the more severe the health status is. The social EQ-5D index tariff may also underestimate the severity in health status at older ages; age appears to correlate with additional health problems not captured by the EQ-5D classification.     

Validity of the Thai EQ-5D in an occupational population in Thailand

Purpose

To assess the construct validity of the Thai EuroQoL (EQ-5D) among an occupational population in Thailand.

Methods

Data were derived from a large cohort study among employees of the Electricity Generating Authority of Thailand. In 2008 and 2009, 4,850 participants completed the Thai EQ-5D and Short-Form 36 version 2 (SF-36v2). Thai preferences weights were used to convert EQ-5D health states into EQ-5D index scores. Construct validity of the Thai EQ-5D was examined by specifying and testing hypotheses about the relationships between the EQ-5D, SF-36v2, and participants’ demographic and medical characteristics.

Results

Construct validity of the Thai EQ-5D was supported by expected relationships with SF-36v2 scale and summary scores. For example, SF-36v2 scores on the mental health scale were much lower for participants who reported having problems on the EQ-5D anxiety/depression dimension compared to those reporting no problems (mean norm-based SF-36v2 scores: 52.9 vs. 41.8, p < 0.001). Additionally, reporting a problem in a given EQ-5D dimension was generally associated with lower SF-36v2 summary scores. The EQ-5D index score distinguished between groups of participants in the expected manner, on the basis of sex, age, education and self-reported health, thus providing evidence of known-groups validity.

Conclusion

The study demonstrated good construct validity of the Thai EQ-5D in a large occupational population in Thailand.     

Validation and comparison of the psychometric properties of the EQ-5D-3L and EQ-5D-5L instruments in Greece

Purpose

To validate and compare the psychometric properties of the EQ-5D-3L with the EQ-5D-5L classification systems in Greece.

Methods

Participants (n = 2279) over 40 years old, sampled from the greater area of Athens using a multistage stratified quota sampling method, completed both EQ-5D versions, while information was also collected on socio-demographics and health-related characteristics. The EQ-5D-5L and EQ-5D-3L were evaluated in terms of agreement, ceiling effects, redistribution and inconsistency, informativity, and convergent and known-groups validity.

Results

The agreement between the EQ-5D-3L and EQ-5D-5L was high (ICC = 0.85). Ceiling effects decreased significantly in the EQ-5D-5L in all domains (P < 0.001), with “usual activities” (?21.4 %) and “self-care” (?20.1 %) showing the highest absolute and “anxiety/depression” the highest relative reduction (?32.46 %). Inconsistency was low (5.7 %). The increase in prevalence of problems was larger than the decrease in their severity, resulting in a lower mean health utility for the EQ-5D-5L. Overall absolute and relative informativity improved by 70.5 % and 16.4 %, respectively, in the EQ-5D-5L. Both instruments exhibited good convergent and known-groups validity, with evidence of a considerably better convergent performance and discriminatory ability of the EQ-5D-5L.

Conclusions

Both EQ-5D versions demonstrated good construct validity and had consistent redistribution. The EQ-5D-5L system may be preferable to the EQ-5D-3L, as it exhibited superior performance in terms of lower ceiling effects, higher absolute and relative informativity, and improved convergent and known-groups validity efficiency.

     

Responsiveness of the generic EQ-5D summary measure compared to the disease-specific EORTC QLQ C-30

Introduction: We investigated whether the sensitivity of the generic health-related quality of life (HRQoL) EQ-5D summary measure (or index) to detect changes over time in a clinical setting is comparable with that of a disease-specific HRQoL questionnaire. Methods: Patients with liver metastases (n = 75) filled out the five domains of the EQ-5D self-classifier, the EQ VAS, and the EORTC QLQ C-30 (a disease-specific (cancer) HRQoL questionnaire). The HRQoL instruments were completed before intervention, and 1/2 month and 3 and 6 months after intervention. Three analyses were performed. First, the EQ-5D index (based on self-classification) was compared to the EQ VAS. Second, the EQ-5D domains were compared to corresponding EORTC QLQ C-30 scales. Third, EQ-5D index and EQ VAS were compared with the EORTC QLQ C-30 global health-status scale. Effect size was chosen as the metric of responsiveness. Results: The EQ-5D index was slightly less responsive than the EQ VAS. Overall, the responsiveness of the EQ-5D index and EQ VAS was equal to the EORTC QLQ C-30 global health-status scale. Conclusion: Despite its generic principle and the apparent crudeness of its framework, the responsiveness of the EQ-5D proved to be comparable to that of a disease-specific HRQoL questionnaire in this specific clinical setting.     

Responsiveness of the EQ-5D Health-Related Quality-of-Life Instrument in Assessing Low Back Pain

ObjectiveTo compare the responsiveness of the EuroQol five-dimensional questionnaire (EQ-5D) generic quality-of-life instrument with that of specific instruments—the Brief Pain Inventory (BPI) and the Oswestry Disability Index (ODI)—in assessing low back pain.MethodsData were obtained from a group of patients receiving epidural steroid injections. We assessed responsiveness by using correlation, by estimating standardized response means, by receiver operating characteristic curve analysis, and by comparing the minimum clinically important differences peculiar to each of the instruments.ResultsODI, BPI, and EQ-5D index scores, and changes in scores, were found to be correlated. Estimated standardized response means and receiver operating characteristic curve analysis suggested lower responsiveness for the EQ-5D index score. Clinically significant categories of mild, moderate, and severe BPI pain intensity translated into progressively and significantly lower mean EQ-5D index scores. An increase or a decrease in severity level reported on any of the five EQ-5D dimensions was associated with significant changes (with appropriate signs) in the condition-specific scores. No change in severity in any EQ-5D dimension was associated with no change in the specific scores. Significant changes in the EQ-5D index scores were associated with clinically important changes in the ODI and BPI scores. Correlation between index scores and responses on EQ-5D’s visual analogue scale was only moderate.ConclusionsThe EQ-5D index is less responsive than instruments specific to pain measurement, although it is capable of indicating clinically important changes. The lower responsiveness arises from EQ-5D’s more limited gradation of severity and its multidimensionality.