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.     

The health status of the Dutch population as assessed by the EQ-6D

This study uses the Six-Dimensional EuroQol instrument (EQ-6D) to describe the health status of the Dutch population and investigates sociodemographic differences. The subjects participated in the second Dutch National Survey of General Practice, which was conducted in 2001. Five percent of all listed patients of 104 practices (99% of the Dutch are listed in a general practice) were invited for a health interview. Analyses were prepared for 9685 respondents aged 18 years or more. The EQ-6D is an extended EQ-5D (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) with a cognitive dimension. The EQ-6D construct validity was examined by comparing it with the SF-36, with good results. Most respondents reported no health problems, while 33% reported pain or discomfort. Women and elderly people generally reported more problems; only depression/anxiety was unrelated to age. Educational level was closely related to problems in all dimensions. The cognitive dimension of the EQ-6D, used for the first time in a general population, gave satisfactory results. This paper includes normative data by age and gender for both the EQ-6D and the EQ-5D. We conclude that the EQ-6D is an efficient tool for establishing the health status in the community, so that different population subgroups can be compared.     

The Construct and Concurrent Validity of the EQ-5D in a Renal Transplant Population

OBJECTIVES: Cost-utility analysis in renal transplant populations requires the use of a generic instrument for health status measurement that generates a single value for health. Such instruments should be widely applicable in diverse patient populations and their validity should be established. The aim of this study was to explore the validity of the EQ-5D in renal transplant patients. METHODS: The EQ-5D was compared with the Short-Form 36 Health Survey (SF-36), the modified transplant symptom occurrence and symptom distress (MTSOSD) scale, the short-form Beck Depression Inventory (BDI), and the State Trait Anxiety Inventory (STAI). Construct and concurrent validity were tested on cross-sectional data of 350 patients. RESULTS: Construct validity is good for some but not all EQ-5D dimensions, and the EQ-5D discriminates well among groups of patients with different health states according to the SF-36, MTSOSD scale, BDI, and STAI and between patients and the general public. Concurrent validity is good, as shown by the correspondence of EQ-5D and SF-36 results. CONCLUSION: It is concluded that the EQ-5D is a valid instrument for the measurement of health status in renal transplant patients.     

Validation of the EQ-5D quality of life instrument in patients after myocardial infarction

Background: We assessed cross-sectional validity of EQ-5D after myocardial infarction (MI). Methods: We compared EQ-5D, SF-36, quality of life After MI (QLMI), and Canadian Cardiovascular Society Anginal Classification (CCSG) scores. Correlation and regression techniques were used to assess convergent validity. SF-36 and alternate Rand-36 scoring were compared. CCSG class was used to evaluate discriminative validity and clinical difference in health state scores. Results: Of 99 patients: mean age 64; median 176.5 days post-MI; 80% had one MI; 74% were CCSG I. 1/3 to 1/2 reported mobility, self-care, pain, and emotional difficulties on EQ-5D. Median health state was 0.73. EQ-5D and SF-36 (or Rand-36) strongly correlate in overall health (0.75), emotional health (0.75), pain (0.68), and activity/ functional (0.5–0.63). EQ-5D and QLMI strongly correlate in activities/ self esteem (0.56), emotional health (0.64), anxiety/depression – restriction (0.53), and overall health (0.5–0.57). EQ-5D self-care correlates weakly with all domains. Domain scores from each general instrument contributed to each other’s overall health score (adjusted R² 0.61–0.69) and to disease specific score (0.45 adjusted R²). EQ-5D discriminates among CCSG classes (p < 0.000). Physicians detected a 0.16 difference in health state scores. Conclusion: The EQ-5D provides valid general HrQOL measurement post-MI.     

Correlations between disease-specific and generic health status questionnaires in patients with advanced COPD: a one-year observational study

ABSTRACT: BACKGROUND: Longitudinal studies analyzing the correlations between disease-specific and generic questionnaires at different time points in patients with advanced COPD are lacking. The aim of this study was to determine whether and to what extent a disease-specific health status questionnaire (Saint George's Respiratory Questionnaire, SGRQ) correlates with generic health status questionnaires (EuroQol-5-Dimensions, EQ-5D; Assessment of Quality of Life instrument, AQoL; Medical Outcomes Study 36-Item Short-Form Health Survey, SF-36) at four different time points in patients with advanced COPD; and to determine the correlation between the changes in these questionnaires during one-year follow-up. METHODS: Demographic and clinical characteristics were assessed in 105 outpatients with advanced COPD at baseline. Disease-specific health status (SGRQ) and generic health status (EQ-5D, AQoL, SF-36) were assessed at baseline, four, eight, and 12 months. Correlations were determined between SGRQ and EQ-5D, AQoL, and SF-36 scores and changes in these scores. Agreement in direction of change was assessed. RESULTS: Eighty-four patients (80%) completed one-year follow-up and were included for analysis. SGRQ total score and EQ-5D index score, AQoL total score and SF-36 Physical Component Summary measure (SF-36 PCS) score were moderately to strongly correlated. The correlation of the changes between the SGRQ total score and EQ-5D index score, AQoL total score, SF-36 PCS, and SF-36 Mental Component Summary measure (SF-36 MCS) score were weak or absent. The direction of changes in SGRQ total scores agreed slightly with the direction of changes in EQ-5D index score, AQoL total score, and SF-36 PCS score. CONCLUSIONS: At four, eight and 12 months after baseline, SGRQ total scores and EQ-5D index scores, AQoL total scores and SF-36 PCS scores were moderately to strongly correlated, while SGRQ total scores were weakly correlated with SF-36 MCS scores. The correlations between changes over time were weak or even absent. Disease-specific health status questionnaires and generic health status questionnaires should be used together to gain complete insight in health status and changes in health status over time in patients with advanced COPD.     

Relationship Among Sociodemographic Factors,Clinical Conditions,and Health-related Quality of Life: Examining the EQ-5D in the U.S. General Population

Introduction: Health-related quality of life (HRQL) measures are used increasingly in evaluations of clinical and population-based outcomes and in economic analyses. We investigate the influence of demographic, socioeconomic, and chronic disease factors on the HRQL of a representative U.S. sample. Methods: We examined data from 13,646 adults in the 2000 Medical Expenditure Panel Survey, a nationally representative sample of the U.S. general population, who completed a self-administered questionnaire containing the EQ-5D, a preference-based measure. We assessed the relationships between EQ-5D scores and sociodemographic variables, including age, sex, race/ethnicity, income and education, and six common chronic conditions. Results: In fully adjusted models, EQ-5D scores decreased with increasing category of age and were lower for persons with a lower income and educational attainment as well as each of the six conditions. Although the EQ-5D scores were lower for females and Whites compared with Blacks such differences were not of a magnitude considered to be clinically important. Conclusions: In the U.S., sociodemographic factors and clinical conditions are strongly associated with scores on the EQ-5D. Population health studies and risk-adjustment models should account and adjust for these factors when assessing the performance of health programs and clinical care.     

A comparison of the responsiveness of different generic health status measures in patients with asthma

Generic health status has been recommended to be measured separately from disease-specific health status, because they can yield complementary information. In particular, generic health status can provide comprehensive health ratings across various disorders. However, the weakness with generic measures is that they may be less responsive to clinical changes than disease-specific ones. Therefore, when using generic health status as an endpoint in clinical trials, the instrument to be used is a problem with respect to responsiveness. In the present study, we investigated and compared the responsiveness of health status measures during asthma treatment using three different generic instruments: the Medical Outcomes Study Short Form 36-items Health Survey (SF-36), the Nottingham Health Profile (NHP) and the EQ5D (EuroQoL), as well as one disease-specific instrument, the Asthma Quality of Life Questionnaire (AQLQ). Fifty-four new patients with asthma who consulted our clinic were recruited. The health status measurements were performed on the initial visit, and at 3 and 6 months. All subscales of the SF-36 showed a significant improvement during the first 6 months. Each dimension of the EQ5D showed stronger ceiling effects than the SF-36. With respect to the responsiveness indices, the SF-36 was regarded as more responsive than the NHP or EQ5D utility. The changes in the SF-36 had a weak to moderate correlation with the changes in the AQLQ. In conclusion, the SF-36 had a higher responsiveness for asthma as a generic measure than the NHP or EQ5D, and evaluated different aspects from the AQLQ. The SF-36 can be used effectively in asthma clinical trials.     

Using the SF-36 and Euroqol on an elderly population

An important methodological issue in measuring health-related quality of life is whether instruments such as SF-36 and EQ can be used on an elderly population. This paper aims to test the completion, reliability and validity of the SF-36 and Euroqol on an elderly female population, and to compare them with the OPCS Disability Survey. Three hundred and eighty women aged 75 and over participated in a randomized controlled trial of the use of clodronate provided the sample. As part of the trial, patients were asked to complete the UK SF-36 and Euroqol, and the OPCS disability survey instrument administered by interview in a hospital clinic at baseline. A random subsample of respondents were retested six months later. The SF-36 achieved poorer levels of completion by dimension (68.1%–88.9%) than the OPCS (99.2%) and Euroqol (84%–93.5%) instruments. There were no major floor effects in the distribution of scores, except for the role dimensions of SF-36. Correlation between test-retest were significant for all instruments, but lower for the role dimensions and social functioning of SF-36, and these dimensions also had 95% Cls for the mean differences in excess of 10 points. There was substantial agreement between the three instruments, and evidence for their construct validity against age and recent use of health services. The sensitivities of the instruments were tested through hypothetical changes in health status. There was some evidence of greater sensitivity to lower levels of morbidity in the SF-36. Where brevity is required and the health changes are expected to be substantial, then EQ may be sufficient. For greater sensitivity SF-36 seems to have an advantage, however lower completion rates and problems with consistency suggest it requires adaptation. One solution would be to use interviewer administration. Another would be to change the SF-36 to make it more suitable for use in elderly people, although this may reduce its usefulness as a generic instrument.     

EQ-5D in a general population survey – A description of the most commonly reported EQ-5D health states using the SF-36

The importance of studying health-related quality of life in the general population has increasingly been emphasized. From a public health perspective, this benefits the identification of population inequalities in health status. One of the currently most popular instruments is the EQ-5D. Evaluations of the EQ-5D generally focus on the overall preference-based index. As this index has a built-in value, exploration of the information from the underlying health states is also important. In this study, the ten most commonly reported EQ-5D health states are described using the SF-36. Data collected in 1999 by questionnaires mailed to a random sample aged 20-74 in south-eastern Sweden were used (n = 9489). Almost 43% reported the best possible EQ-5D health state and 78% were accounted for by three EQ-5D health states. The EQ-5D health state classification was largely reflected by the SF-36, with the EQ-5D items mobility, usual activities, pain/discomfort and anxiety/depression tapping most clearly on the SF-36 scales physical functioning, role limitations due to physical health problems, bodily pain, and mental health, respectively. However, within the same level of EQ-5D (i.e., moderate problems) there was a rather large variation of SF-36 scale scores, particularly regarding the EQ-5D item pain/discomfort and the SF-36 scale BP.     

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.     

Use of the SF-12 instrument for measuring the health of homeless persons

OBJECTIVE: To evaluate the construct validity of the Short Form 12-item Survey (SF-12) among users of a homeless day shelter. Adding brief health assessments has potential to provide information regarding the effect that programs have upon the health status and functioning of homeless persons. STUDY SETTING: A convenience sample of 145 homeless persons at a day shelter in an urban setting. STUDY DESIGN: Participants were verbally administered the SF-12 that provides information on mental and physical health status and the Dartmouth Improve Your Medical Care Survey (IYMC) that provides information on functional health, clinical symptoms, medical conditions, and health risk. The IYMC survey system has been widely used in clinical settings to assess health status and the outcomes of care. DATA COLLECTION/EXTRACTION METHODS: Construct validity was assessed by the following approaches: (a) the method of extreme groups was used where multivariate analysis of variance determined if SF-12 summary scores varied for individuals who differed in self-reported clinical symptoms and medical conditions, and (b) convergent validity was assessed by correlating SF-12 summary scores with the subscales. PRINCIPAL FINDINGS: Four to 10 point differences in physical health (PCS12) and 5-11 point differences in mental health (MCS12) were found between those who reported acute symptoms and medical conditions and those who did not. A 13-point difference in PCS12 scores and a 7-16-point difference in MCS12 scores were found for those who reported none or few to several symptoms or conditions. The summary scores and subscales yielded satisfactory convergent validity coefficients that ranged from 0.62 to 0.88 with one exception. CONCLUSIONS: The SF-12 shows promise as a valid outcome indicator for assessing and monitoring health status among the homeless. Its strengths include brevity and availability of norms for specific medical conditions.     

Do personal and societal preferences differ by socio‐demographic group?

For equity, preferences used in cost-effectiveness analyses (CEAs) should yield similar values for different groups with similar health states. We used data from the US 2000 Medical Expenditure Panel Survey, including socio-demographics, EQ-5D Index and EQ Visual Analog Scale (EQ VAS) scores, to examine whether EQ-5D Index (representing community preferences) and EQ VAS (representing personal preferences) scores differed systematically by socio-demographic group. Differences between EQ-5D Index and EQ VAS scores by socio-demographic group were small and mostly not statistically significant. These preliminary findings suggest that using the EQ-5D Index in CEAs may not contribute to socio-demographic inequities.     

An evaluation of patient-reported outcome measures in lower limb reconstruction surgery

Purpose

To assess the measurement properties (acceptability, validity, reliability and responsiveness), of the MOS 36-Item Short-Form Health Survey (SF-36), the EQ-5D, the Short-Form McGill Pain Questionnaire (SF-MPQ) and the Musculoskeletal Functional Assessment Instrument (MFA), in patients who have undergone limb reconstruction surgery (LRS).

Methods

Four instruments measuring patient-reported outcome were completed at baseline and 12?months from surgery.

Results

101 LRS patients were recruited with 95 responding at baseline and 71 at a 12-month follow-up. Response rates at baseline were over 94%. In three instruments, there was evidence of floor or ceiling effect, the exception being the EQ-5D. Cronbach??s ?? statistics of internal consistency reliability were acceptable at ??0.80 for all dimensions of the MFA, the SF-MPQ PRI(S) and seven of the SF-36 dimensions. When comparing mean changes in scores between baseline and 12?months, the most responsive measure was the SF-36 with an average Standardised Response Mean of 0.48 for those who reported their health as better. Statistically significant differences were observed between the health change groups (??worse??, ??better?? and ??same??) for four dimensions of the SF-36, the two summary scores and the SF-6D.

Conclusions

Variation and poor performance of some of the instruments resulted in a recommendation of using the SF-36 and the SF-6D for LRS patients.     

Assessing quality of life in the elderly: a direct comparison of the EQ-5D and AQoL

As more research is undertaken on the elderly, accurately assessing changes in their quality of life becomes increasingly important. Generic instruments are the most popular method to assess quality of life, and one of the most widely used is the EQ-5D. However, the range of dimensions, sensitivity of scales and completion rates have been raised as concerns when using this measure with the elderly. The AQoL is a newer instrument which offers greater richness in dimensions of health covered, and potentially offers greater sensitivity to changes in quality of life. This paper presents the results of a 'head-to-head' comparison of the EQ-5D and AQoL in terms of practicality, construct validity, agreement (of absolute scores and their change over time) and sensitivity to change, as part of a randomised controlled trial in the elderly. Poor agreement was found between both the absolute scores from each instrument and change in scores over time. Although the AQoL appeared to have more favourable construct validity, the EQ-5D was easier to administer, had a higher completion rate, and appeared more sensitive to change. We conclude that the AQoL is probably less well suited to measuring health status in a very elderly population than the EQ-5D.     

An assessment of the discriminative ability of the EQ-5D<Subscript>index</Subscript>, SF-6D,and EQ VAS,using sociodemographic factors and clinical conditions

OBJECTIVE: To assess whether three health-related quality-of-life (HRQL) measures (the EQ-5D(index), SF-6D, and EQ VAS) can discriminate between the HRQL of different groups of individuals. METHODS: In one UK general practice a cross-sectional survey requested information on six sociodemographic factors, 10 clinical conditions, and the three HRQL measures. Regression analyses were used to assess whether there was a significant difference in HRQL between groups with different sociodemographic factors and those with and without clinical conditions. RESULTS: One thousand eight hundred and sixty-five questionnaires were returned. There was a significant difference between the HRQL of the majority of different groups according to each HRQL measure. However, not all of the measures could discriminate between groups of different ethnicity, gender, or smoking status, or those with and without asthma, stroke, cancer or diabetes. CONCLUSION: The HRQL of the majority of different groups could be discriminated between by the EQ-5D(index), SF-6D, and EQ VAS.