Psychometric properties comparison between EQ-5D-5L and EQ-5D-3L in the general Thai population

Comparing the EQ-5D-5L and stroke impact scale 2.0 in stroke patients: an analysis of measurement properties

BACKGROUND

Stroke has evolved to become a chronic disease and a major public health challenge. To adequately capture the full disease burden of stroke patients, the assessment of health-related quality of life (HRQoL) and thus the performance of respective measures is increasingly relevant. The aim of this analysis was to compare the measurement properties of two self-report instruments, the EQ-5D-5L and the Stroke Impact Scale 2.0.

METHODS

The data used for the analysis was derived from a quasi-experimental case management study for mildly to moderately affected incident stroke and transient ischemic attack (TIA) patients aged ≥ 18 in Germany. Data was collected patient-individually at 3, 6 and 12 months after initial stroke. The EQ-5D-5L and SIS 2.0 were compared in terms of feasibility, ceiling and floor effects, responsiveness and known-groups validity (Kruskal-Wallis H and Wilcoxon rank-sum test).

RESULTS

A response for all three follow-ups is available for n = 855 patients. The feasibility of the EQ-5D-5L is determined as good (completion rate: 96.4-96.6%, ≥ one item missing: 3.2 - 3.3%), whereas the SIS 2.0 is moderately feasible (overall completion rate: 44.9-46.1%, ≥ one item missing in domains: 4.7 - 28.7%). The SIS 2.0 shows substantial ceiling effects in comparable domains (physical function: 10.4 - 13%, others: 3.5-31.3%) which are mainly larger than ceiling effects in the EQ-5D-5L index (17.1-21.5%). In terms of responsiveness, the EQ-5D-5L shows small to moderate change while the SIS 2.0 presents with moderate to large responsiveness. The EQ-5D-5L index, mobility, usual activities and Visual Analogue Scale show known-groups validity (p < 0.05). Content-related domains of the SIS 2.0 show known-groups validity as well (p < 0.05). However, it is compromised in the emotion domain in both measures (p > 0.05).

CONCLUSIONS

The EQ-5D-5L seems to be slightly more suitable for this cohort. Nonetheless, the results of both measures indicate limited suitability for TIA patients. Large-scale studies concerning responsiveness and known-groups validity are encouraged.

TRIAL REGISTRATION

The study was registered in the German Clinical Trials Register, retrospective registration on 21.09.2022.

REGISTRATION ID

DRKS00030297.

Exploring potential EQ-5D bolt-on dimensions with a qualitative approach: an interview study in Hong Kong SAR, China

PURPOSE

The introduction of bolt-on dimensions in EQ-5D instruments is growing common, but most bolt-on studies have targeted the diseased population and obtained bolt-on from other existing Health-related Quality of Life (HRQoL) instruments. As the qualitative approach offers important evidence to support the consistency and design of the potential bolt-on items, this paper studies the Hong Kong SAR community's perception of the current EQ-5D-5 L instrument and identifies potential bolt-on via a qualitative approach.

METHODS

A representative sample mix was recruited based on the age group, gender, and education level composition of the Hong Kong SAR community by quota sampling. Semi-structured interviews were conducted and the interviews were transcribed and coded to identify emergent and recurrent themes.

RESULTS

Thirty interviews were conducted and the majority of the interviewees considered the EQ-5D-5 L insufficiently comprehensive to illustrate their HRQoL. While some key HRQoL aspects included in the EQ-5D matched with the community's HRQoL perception, respondents showed concern about the potential overlap of the existing HRQoL dimension, the optimal number or attributes, and the appropriateness of the EQ-VAS. Among the potential bolt-on dimensions that emerged, 'Sleep', 'Interpersonal Relationship', and 'Satisfaction' were the key potential bolt-on dimensions identified and emphasized in the interviews.

CONCLUSIONS

The qualitative findings of the study illustrate the possible gap between EQ-5D-5 L measurements and community HRQoL perception, while the findings support the development of EQ-5D bolt-on dimensions in the target community with content and face validity.

EQ-5D-3L and EQ-5D-5L population norms for Thailand

BACKGROUND

The previous Thai norm-based scores for the EQ-5D-5L were established with Thai general population samples aged 20-70 years in 2019. Nevertheless, these values need to be updated after the COVID-19 pandemic because of its effects on both physical and mental health. This study therefore aimed to establish population norms of the Thai EQ-5D-3L, EQ-5D-5L and EQ-VAS scores as well as to estimate disutility values associated with self-reported main diseases.

METHODS

Individual face-to-face interviews were conducted with 2000 adult (age ≥ 18 years) members of the general Thai population to estimate norm-based scores. Each participant completed the EQ-5D-3L and EQ-5D-5L as well as questions related to their sociodemographic factors and self-reported main diseases. Responses to the two instruments were converted to health utility (HU) scores on the basis of available value sets. Descriptive statistics were used to report the norm-based scores stratified by age and sex categories. Response redistribution determining the response consistency between EQ-5D versions was investigated. The HU score agreement from those two instruments was investigated using intraclass correlation coefficient (ICC). Tobit regression models were employed to investigate the relationships between sociodemographic factors and HU and EQ-VAS scores. Moreover, it was used to estimate the disutility values associated with self-reported main diseases.

RESULTS

The means (percentage of ceiling effects) of EQ-5D-3L, EQ-5D-5L, and EQ-VAS scores were 0.845 (57.80%), 0.923 (49.05%), and 79.83 (3.20%), respectively. The average percentage of inconsistent response was 1.09%. A good agreement level was found between both EQ-5D versions with the ICCs of 0.789 (95% CI: 0.558-0.878). Female, older, and unemployed participants and those with BMI ≥ 30 reported lower EQ-5D-3L and EQ-5D-5L than their counterparts. Bone/Joint disorder and stroke contributed to the largest disutility value for those two instruments.

CONCLUSIONS

The Thai norm-based scores from those two instruments were diminished when advancing age and among female, unemployed, and obese (BMI ≥ 30) participants. It is expected to provide information to policy makers to better allocate health care resources to those with diminished norm-based scores.

Psychometric performance of EQ-5D-5L and SF-6Dv2 in patients with lymphoma in China

AIM

To assess and compare the measurement properties of EQ-5D-5L and SF-6Dv2 among lymphoma patients in China.

METHODS

A face-to-face survey of Chinese lymphoma patients was conducted at baseline (all types) and follow-up (diffuse large B-cell). EQ-5D-5L and SF-6Dv2 health utility scores (HUSs) were calculated using the respective Chinese value sets. Ceiling effect was assessed by calculating the percentage of respondents reporting the optimal health state. Convergent validity of EQ-5D-5L and SF-6Dv2 was assessed using the Spearman rank correlation coefficient (r) with QLQ-C30 as a calibration standard. Known-groups validity of the two HUSs was evaluated by comparing their scores of patients with different conditions; and their sensitivity was further assessed in the known-groups using relative efficiency (RE). Test-retest reliability and responsiveness was tested using ICC and standardized response mean (SRM), respectively.

RESULTS

Altogether 200 patients were enrolled at baseline and 78 were followed up. No ceiling effect was found for SF-6Dv2 compared to 24.5% for EQ-5D-5L. Correlation between the two HUSs and with QLQ-C30 score was strong (r > 0.5). Each dimension of EQ-5D-5L and SF-6Dv2 had moderate or greater correlations with similar dimensions of QLQ-C30 (r > 0.35). Both EQ-5D-5L and SF-6Dv2 could only a minority known-groups, and the latter may have better sensitivity. EQ-5D-5L had better test-retest reliability (ICC = 0.939); while both of them were responsive to patients with worsened and improved clinical status.

CONCLUSIONS

EQ-5D-5L and SF-6Dv2 were found to have good convergent validity and responsiveness, while EQ-5D-5L had better test-retest reliability and higher ceiling effect. Not enough evidence indicates which of the two measures has better known-group validity and sensitivity.

Psychometric evaluation of the WHOQOL-BREF and its shorter versions for general Thai population: confirmatory factor analysis and Rasch analysis

PURPOSE

Rasch analysis was employed to validate the World Health Organization Quality of Life-BREF (WHOQOL-BREF) and its existing shorter versions in the general Thai population.

METHODS

1200 respondents were randomly selected to complete the questionnaire. Confirmatory factor analysis (CFA) was employed to test the structure of the WHOQOL-BREF and its shorter versions with the random sub-sample of 900 respondents, while Rasch analysis was performed with a random sub-sample of 300 respondents.

RESULTS

The CFA confirmed the factor structure of WHOQOL-BREF and its shorter versions. The Rasch analysis revealed that the WHOQOL-BREF, when a four-domain structure was tested using a subtest approach, achieved acceptable model fit to the Rasch model and met the expectations of unidimensionality with high reliability (PSI = 0.87). Individual domain models were also unidimensional, but reliability of the 3-item social domain was inadequate. While the 8-item EUROHIS-QOL-8 and 5-item WHOQOL-5 achieved an overall acceptable fit and met the expectations of unidimensionality, the reliability of the WHOQOL-5 was below the acceptable threshold (PSI = 0.66). Reliability of the EUROHIS-QOL-8 was satisfactory (PSI = 0.79).

CONCLUSIONS

The WHOQOL-BREF is a valid instrument for use in the Thai general population, both as a total score as well as individual subscales. Rasch analysis also supports the use of EUROHIS-QOL-8, but the WHOQOL-5 lacks good reliability. While the reliability of the EUROHIS-QOL-8 is sufficiently high for between-group analysis, the Thai WHOQOL-BREF total score can also be used for within-participant analyses. Rasch investigation with a more varied health conditions of general Thai samples or patient groups is encouraged for future studies.

A culturally adapted manual-assisted problem-solving intervention (CMAP) for adults with a history of self-harm: a multi-centre randomised controlled trial

BACKGROUND

Self-harm is an important predictor of a suicide death. Culturally appropriate strategies for the prevention of self-harm and suicide are needed but the evidence is very limited from low- and middle-income countries (LMICs). This study aims to investigate the effectiveness of a culturally adapted manual-assisted problem-solving intervention (CMAP) for patients presenting after self-harm.

METHODS

This was a rater-blind, multicenter randomised controlled trial. The study sites were all participating emergency departments, medical wards of general hospitals and primary care centres in Karachi, Lahore, Rawalpindi, Peshawar, and Quetta, Pakistan. Patients presenting after a self-harm episode (n = 901) to participating recruitment sites were assessed and randomised (1:1) to one of the two arms; CMAP with enhanced treatment as usual (E-TAU) or E-TAU. The intervention (CMAP) is a manual-assisted, cognitive behaviour therapy (CBT)-informed problem-focused therapy, comprising six one-to-one sessions delivered over three months. Repetition of self-harm at 12-month post-randomisation was the primary outcome and secondary outcomes included suicidal ideation, hopelessness, depression, health-related quality of life (QoL), coping resources, and level of satisfaction with service received, assessed at baseline, 3-, 6-, 9-, and 12-month post-randomisation. The trial is registered on ClinicalTrials.gov. NCT02742922 (April 2016).

RESULTS

We screened 3786 patients for eligibility and 901 eligible, consented patients were randomly assigned to the CMAP plus E-TAU arm (n = 440) and E-TAU arm (N = 461). The number of self-harm repetitions for CMAP plus E-TAU was lower (n = 17) compared to the E-TAU arm (n = 23) at 12-month post-randomisation, but the difference was not statistically significant (p = 0.407). There was a statistically and clinically significant reduction in other outcomes including suicidal ideation (- 3.6 (- 4.9, - 2.4)), depression (- 7.1 (- 8.7, - 5.4)), hopelessness (- 2.6 (- 3.4, - 1.8), and improvement in health-related QoL and coping resources after completion of the intervention in the CMAP plus E-TAU arm compared to the E-TAU arm. The effect was sustained at 12-month follow-up for all the outcomes except for suicidal ideation and hopelessness. On suicidal ideation and hopelessness, participants in the intervention arm scored lower compared to the E-TAU arm but the difference was not statistically significant, though the participants in both arms were in low-risk category at 12-month follow-up. The improvement in both arms is explained by the established role of enhanced care in suicide prevention.

CONCLUSIONS

Suicidal ideation is considered an important target for the prevention of suicide, therefore, CMAP intervention should be considered for inclusion in the self-harm and suicide prevention guidelines. Given the improvement in the E-TAU arm, the potential use of brief interventions such as regular contact requires further exploration.

A head-to-head comparison of well-being of older people (WOOP) and EQ-5D-5L in patients, carers and general public in China

Recently, well-being of older people measure (WOOP) was developed and validated in a Dutch population. Although WOOP was developed targeting the older people, it has the potential for use in a wider population. In this study, we aimed to examine the relationship between WOOP and EQ-5D-5L and compared their psychometric properties in a sample of patients, carers and healthy general public covering a wider age group. We conducted a cross-sectional study in Guizhou Province, China between July and August 2022. Data was collected using paper and pencil. We analysed and reported the acceptability, item response distribution, the Spearman correlation coefficients of all items, the Exploratory Factor Analysis (EFA) of all items, the known-group validity and the convergent validity of EQ-5D-5L utility and WOOP utility. A total of 322 participants completed the survey with 105 patients, 101 carers and 116 healthy general public. 9% of participants had at least one missing response. Three items of WOOP did not have any level 5 responses and EQ-5D-5L had more level 1 responses. The correlations were low between EQ-5D-5L and WOOP items and the three-factor EFA showed these two instruments had only one shared factor and the other two factors were only related to WOOP items. Younger people had lower missing response rate and a different response distribution for three items. WOOP measures a broader construct beyond health while EQ-5D-5L is a more sensitive instrument when health is considered alone. There is a potential of using WOOP in a wider population.

Normative profile of the EQ-5D-5L dimensions, EQ-5D-5L index and EQ-VAS scores for the general Thai population

PURPOSE

To generate a normative profile for the EQ-5D-5L dimensions, EQ-5D-5L index, and EQ-VAS scores of the general Thai population and to examine the associations between sociodemographic characteristics and their norm-based scores.

METHODS

Data from 2019 general Thai samples were employed to estimate the norm-based scores elicited using the Thai EQ-5D-5L value set. Descriptive statistics were used to estimate the norm-based scores stratified by gender and six age bands to obtain the normative profile for the general Thai population. Multivariable logistic and Tobit regression models were used to investigate the relationships between sociodemographic characteristics and EQ-5D-5L dimensions, EQ-5D-5L index, and EQ-VAS scores.

RESULTS

The mean EQ-5D-5L index and EQ-VAS scores were 0.931 and 82.3, respectively. Approximately 88.9% of the participants reported 19 out of 3125 (3%) possible health states. The odds of having problems with mobility was greatest for the sample aged ≥ 65 years and declined with decreasing age. Women, samples with advancing age, and those with a household income of ≤ 10,000 Baht/month and fair and poor health perceptions were more likely to report a lower EQ-5D-5L index. Furthermore, advanced age and fair and poor health perception were significantly associated with lower EQ-VAS scores.

CONCLUSION

The EQ-5D-5L population norms were established as the benchmark for both EQ-5D-5L index and EQ-VAS scores for the general Thai population. This is expected to support the health service research and inform policymakers on the allocation of limited healthcare resources.

Mapping of the World Health Organization Quality of Life Brief (WHOQOL-BREF) to the EQ-5D-5L in the General Thai Population

PURPOSE

This study aimed at mapping the World Health Organization Quality of Life Brief (WHOQOL-BREF) and the EQ-5D-5L in the general Thai population and to determine the impact on the incremental cost-utility ratio (ICUR) through five hypothetical scenarios.

METHODS

A total of 1,200 Thai participants were randomly allocated into the 'estimation' and 'validation' groups. A curve estimation with nine regression models was performed to identify the best-fit regression model of significant WHOQOL-BREF dimension scores for the EQ-5D-5L index score predictions in the estimation group. The identified model was then used for the calculation of the predicted EQ-5D-5L index scores in the validation group. The percentage change from the hypothetical base-case scenario with predefined parameters was used to determine the impact on the ICUR.

RESULTS

An inverse model was the best-fit regression model to predict the EQ-5D-5L index scores. The absolute difference between the predicted and observed index scores was 0.064, and the percentage of the sample that was mispredicted by ≥ 0.05 and ≥ 0.1 was 43.8% and 16.8%, respectively. Moreover, the percentage change in ICUR ranged between 0.13 and 1.84% from the hypothetical base-case scenario.

CONCLUSIONS

An inverse relationship between the studied scores was identified. The minimal impact on the ICUR suggests that the Health Utility Index of the mapped equation can be applied to economic analyses.

Psychometric properties of the EQ-5D-5L compared with EQ-5D-3L in cancer patients in Iran

Background and Objective

Psychometric evidence to support the validity and reliability of the EuroQol-5 Dimensions (EQ-5D) in cancer patients is limited. This study aimed to test the validity and reliability of the EQ-5D-5L (5L) in comparison with EQ-5D-3L (3L) in cancer patients.

Methods

Data of 650 cancer patients were collected through consecutive sampling method from three largest governmental cancer centers in Iran between June 2021 and January 2022. The data were gathered using the 3L, 5L, and the European Organization for Research and Treatment of Cancer quality of life questionnaire (QLQ-C30) instruments. The 3L and 5L were compared in terms of ceiling effect, discriminatory power, convergent and known-groups validity, relative efficiency, inconsistency, agreement, and reliability.

Results

Compared with the 3L, ceiling effect decreased by 27.86%. Absolute and relative informativity of discriminatory power improved by 45.93% and 22.92% in the 5L, respectively. All convergent validity coefficients with 5L were stronger than with 3L. Both 3L and 5L demonstrated good known-groups validity, and the relative efficiency was higher for 5L in 4 out of 7 patients' characteristics. The two instruments showed low overall inconsistency (1.45%) and 92.57% of the differences of observations between the 3L and 5L were within the 95% limit of agreement. The interclass correlation coefficient (ICC) for 3L and 5L indexes were 0.88 and 0.85, respectively, and kappa coefficients in the 3L dimensions (range=0.66-0.92) were higher than the 5L(range=0.64-0.79).

Conclusions

The 5L demonstrated to be better than the 3L in terms of ceiling effect, inconsistency, discriminatory power, convergent validity, relative efficiency.

The relationship between anthropometric indicators and health-related quality of life in a community-based adult population: A cross-sectional study in Southern China

Background

This study was designed to analyze the relationship of waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), relative fat mass (RFM), lipid accumulation product (LAP) and health-related quality of life (HRQoL) in the community-dwelling population of southern China and to explore the independent contribution of socio-demographic characteristics, number of chronic diseases and anthropometric indicators to HRQoL in that population.

Methods

This community-based cross-sectional survey studied 2,663 adults aged 18 years and older. HRQoL was assessed by the 3-level EuroQol 5-dimensional scale (EQ-5D-3L), and HRQoL were calculated using the Chinese EQ-5D-3L value set. The outcome variable was the EQ-5D-3L score (HRQoL). Cluster regression was used to analyse the independent contribution of each obesity indicator to HRQoL.

Results

A total of 2,663 people participated in this study, and their mean EQ-5D-3L score was 0.938 ± 0.072. In this study, according to the results of the one-way ANOVA, HRQoL was significantly different between the groups of WHtR, WHR, RFM and LAP, respectively. The independent contributions of socio-demographic factors, number of chronic diseases and anthropometric measures to HRQoL in the whole population accounted for 76.2, 7.9, and 15.9% of the total effect, respectively.

Conclusion

RFM and LAP were found to have a previously unreported negative impact on HRQoL in a community-dwelling population. In future studies, RFM and LAP could be used as new indicators of obesity to predict quality of life in humans.

A Comparison of EQ-5D-3L, EQ-5D-5L, and SF-6D Utilities of Patients with Musculoskeletal Disorders of Different Severity: A Health-Related Quality of Life Approach

This study compares EQ-5D-3L, EQ-5D-5L, and SF-6D utilities in patients with different musculoskeletal (MSK) disorders, also differing in disease severity as defined by valid clinical indexes. Utilities were measured from a cross-sectional sample of rheumatoid arthritis (N = 114), psoriatic arthritis (N = 57), ankylosing spondylitis (N = 49), and osteopenia/osteoporosis (N = 95) patients. For the first three groups, disease activity (severity) was measured with the DAS-28, DAPSA, and BASDAI clinical indexes, respectively. Mean differences and effect sizes were measured, and agreement between utilities was estimated with the intraclass correlation coefficient and Bland−Altman plots. Higher agreement was observed between EQ-5D-5L and SF-6D, compared to EQ-5D-3L and SF-6D, in all MSK disorder groups and severity levels. In groups with moderate to high severity, agreement between EQ-5D-3L/SF-6D and EQ-5D-5L/SF-6D was between low and fair, and both EQ-5D-3L and 5L utilities were lower than SF-6D (p < 0.001). On the other hand, in remission or low activity groups, agreement was excellent, and SF-6D utilities were again typically higher than EQ-5D-3L/5L, but not significantly. In more severe patients, SF-6D generated significantly higher utilities than EQ-5D-3L and 5L, which is consistent with most previous studies. Such discrepancies could have implications on economic evaluations of interventions targeting patients with MSK disorders.

Evaluation of the EQ-5D-3L and 5L versions in low back pain patients

Background

The EuroQol EQ-5D is one of the most widely researched and applied patient-reported outcome measures worldwide. The original EQ-5D-3L and more recent EQ-5D-5L include three and five response categories respectively. Evidence from healthy and sick populations shows that the additional two response categories improve measurement properties but there has not been a concurrent comparison of the two versions in patients with low back pain (LBP).

Methods

LBP patients taking part in a multicenter randomized controlled trial of lumbar total disc replacement and conservative treatment completed the EQ-5D-3L and 5L in an eight-year follow-up questionnaire. The 3L and 5L were assessed for aspects of data quality including missing data, floor and ceiling effects, response consistency, and based on a priori hypotheses, associations with the Oswestry Disability Index (ODI), Pain-Visual Analogue Scales and Hopkins Symptom Checklist (HSCL-25).

Results

At the eight-year follow-up, 151 (87%) patients were available and 146 completed both the 3L and 5L. Levels of missing data were the same for the two versions. Compared to the EQ-5D-5L, the 3L had significantly higher floor (pain discomfort) and ceiling effects (mobility, self-care, pain/discomfort, anxiety/depression). For these patients the EQ-5D-5L described 73 health states compared to 28 for the 3L. Shannon’s indices showed the 5L outperformed the 3L in tests of classification efficiency. Correlations with the ODI, Pain-VAS and HSCL-25 were largely as hypothesized, the 5L having slightly higher correlations than the 3L.

Conclusion

The EQ-5D assesses important aspect of health in LBP patients and the 5L improves upon the 3L in this respect. The EQ-5D-5L is recommended in preference to the 3L version, however, further testing in other back pain populations together with additional measurement properties, including responsiveness to change, is recommended.

Trial registration: retrospectively registered: https://clinicaltrials.gov/ct2/show/NCT01704677.

The measurement performance of the EQ-5D-5L versus EQ-5D-3L in patients with hidradenitis suppurativa

PURPOSE

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that affects up to 1% of the population in Europe. The EQ-5D is the most commonly used generic instrument for measuring health-related quality of life among HS patients. This study aims to compare the measurement properties of the two adult versions of EQ-5D (EQ-5D-3L and EQ-5D-5L) in patients with HS.

METHODS

We recruited 200 consecutive patients with HS (mean age 37 years, 38% severe or very severe HS) to participate in a multicentre cross-sectional survey. Patients completed the EQ-5D-3L, EQ-5D-5L, Dermatology Life Quality Index (DLQI) and Skindex-16 questionnaires.

RESULTS

More than twice as many different health state profiles occurred in the EQ-5D-5L compared to the EQ-5D-3L (101 vs. 43). A significant reduction in ceiling effect was found for the mobility, self-care and usual activities dimensions. A good agreement was established between the EQ-5D-3L and EQ-5D-5L with an intraclass correlation coefficient of 0.872 (95% CI 0.830-0.903; p < 0.001) that was confirmed by a Bland-Altman plot. EQ-5D-5L improved both the absolute and relative informativity in all dimensions except for anxiety/depression. EQ-5D-3L and EQ-5D-5L demonstrated similar convergent validity with DLQI and Skindex-16. EQ-5D-5L was able to better discriminate between known groups of patients based on the number of comorbidities and disease severity (HS-Physician's Global Assessment).

CONCLUSION

In patients with HS, the EQ-5D-5L outperformed the EQ-5D-3L in feasibility, ceiling effects, informativity and known-groups validity for many important clinical characteristics. We recommend using the EQ-5D-5L in HS patients across various settings, including clinical care, research and economic evaluations.

A comparison of measurement properties between UK SF-6D and English EQ-5D-5L and Thai EQ-5D-5L value sets in general Thai population

BACKGROUND

Evidence is limited for comparative psychometric properties between EQ-5D-5L and SF-6D. Therefore, this study compared psychometric properties between those instruments using value sets from Thailand, England, and the UK in the general Thai population.

METHODS

A total of 1,200 participants were recruited. The agreement level was evaluated using intraclass correlation coefficients (ICCs) and Bland-Altman plots. Convergent validity with SF-12v2 was assessed by Spearman's rho correlations. Known-group validity compared discriminant activity and sensitivity between groups. Responsiveness was assessed using standardized effect sizes (SES) and standardized response mean (SRM).

RESULTS

Agreement between SF-6D and Thai (ICCs = 0.51) and English (ICCs = 0.52) EQ-5D-5L index scores was good. The physical functioning demonstrated moderate to strong and moderate correlations with Thai (r = 0.50) and English (r = 0.46) EQ-5D-5L index scores, whereas SF-6D index scores strongly correlated with role emotion (r = 0.81). EQ-5D-5L was better than SF-6D at discrimination and sensitivity for gender, age, education level, household income, and number of diseases. The SF-6D was more responsive than the EQ-5D-5L for the worsened group.

CONCLUSION

Both SF-6D and EQ-5D-5L are valid among the general Thai population. Further studies should reinvestigate responsiveness and determine their impacts on economic analyses among patient groups.