Cross-cultural measurement equivalence of the EQ-5D-5L items for English-speaking Asians in Singapore

Intermittently scanned continuous glucose monitoring provides no benefit over structured self-monitoring of blood glucose in type 2 diabetes not on prandial insulin, in the context of diabetes self-management education: GLucose monitoring programme SingaporE (GLiMPSE)

OBJECTIVE

We evaluated the impact of intermittently scanned continuous glucose monitoring(is-CGM)over self-monitoring of blood glucose(SMBG) in the context of diabetes self-management education (DSME) in sub-optimally controlled type 2 diabetes(T2D) in a multi-ethnicsetting.

RESEARCH DESIGN AND METHOD

Randomized-controlled, open-label trial (NCT04564911), of T2D with HbA1c ≥ 7.5-≤10 %, on oral agents with/without basal insulin was carried out. Intervention arm received 6 weeks(w) continuous is-CGM, followed by one is-CGM/month till 24w. Control arm was advised to perform 4 SMBG/day. Educationwas delivered at weeks 0, 2, 8, 16.

PRIMARY OUTCOME

Change in HbA1c from baseline at 24w. Modified intention-to-treat (mITT) analysis with linear mixed-effect model for repeated measurementswas performed.

RESULTS

176 subjects, age 55 ± 10.7 years(y), DM duration 11 ± 7.3y, BMI 27.8 ± 5.9 kg/m2, 58 % Male, 29.5 % basal insulin users were analysed. Within each arm,from baseline to 24w, mean HbA1c decreasedby -0.6 % (-6.6.mmol/mol, p-value < 0.01)and weight decreased(isCGM: -1.44 kg; SMBG: -1.25 kg, both p < 0.01). These changes were sustained to one year. However, there wasno significant difference in these parameters between arms (p-value > 0.05).

CONCLUSION

In the context of DSME, use of either SMBG or is-CGM led to improved glycaemia and reduced weight over a period of 24 weeks, sustained to one year.

ENABLE-SG (Educate, Nurture, Advise, Before Life Ends for Singapore) as a proactive palliative care model: protocol for a hybrid type 1 effectiveness-implementation randomized wait-list controlled trial

BACKGROUND

Specialist palliative care is often provided late in the patient's disease trajectory in response to uncontrolled symptoms. Shifting from this reactionary illness-stress paradigm to a proactive health-wellness approach, the ENABLE (Educate, Nurture, Advise, Before Life Ends) telehealth model aims to enhance the coping, stress and symptom management, self-care, and advance care planning skills of patients with advanced cancers and their caregivers. The ENABLE model has been culturally adapted to Singapore (ENABLE-SG) and pilot-tested. A hybrid type 1 effectiveness-implementation design will be used to evaluate the effectiveness of ENABLE-SG while collecting real-world implementation data.

METHODS

This single-centre, assessor-blind, wait-list (immediately vs. 6 months) randomized controlled trial will recruit 300 adult patients within 60 days of an advanced cancer diagnosis and their family caregivers from the National Cancer Centre of Singapore. ENABLE-SG comprises structured psychoeducational sessions with a telehealth coach, covering essential topics of early palliative care. Participants will be assessed at baseline and every 3 months until patient's death, 12 months (caregivers), or end of study (patients). The primary outcome is patient quality of life 6 months after baseline. Secondary patient-reported outcomes include mood, coping, palliative care concerns, and health status. Secondary caregiver-reported outcomes include caregiver quality of life, mood, coping, and care satisfaction. Mixed-effects regression modelling for repeated measurements will be used. To assess the effectiveness of ENABLE-SG versus usual care, patient and caregiver outcomes at 6 months will be compared. To compare earlier versus delayed ENABLE-SG, patient and caregiver outcomes at 12 months will be compared. Within the hybrid type 1 effectiveness-implementation design, implementation outcomes will be evaluated in both the early and delayed groups. Acceptability, adoption, appropriateness, and feasibility will be assessed using a feedback survey and semi-structured interviews with a purposive sample of patients, caregivers, and healthcare providers. Transcribed interviews will be analysed thematically. Other implementation outcomes of penetration, fidelity, and cost will be assessed using records of study-related processes and summarized using descriptive statistics. A cost-effectiveness analysis will also be conducted.

DISCUSSION

This study will assess both effectiveness and implementation of ENABLE-SG. Insights into implementation processes can facilitate model expansion and upscaling.

TRIAL REGISTRATION

Registered prospectively on ClinicalTrials.gov, NCT06044441. Registered on 21/09/2023.

Prospective study on the clinical and economic burden of venous leg ulcers in the tropics

OBJECTIVE

Venous leg ulcers (VLUs) are both chronic and recurrent. The treatment of such ulcers often require multiple outpatient visits and dressing changes. Several reports on the costs of treating such VLUs have been reported in the west. We prospectively evaluated the clinical and economic burden of VLUs in a population of Asian patients in the tropics.

METHODS

Patients from a prospective two-center study conducted at two tertiary hospitals in Singapore, as a part of the Wound Care Innovation in the Tropics program, between August 2018 and September 2021 were recruited. The patients were followed up for 12 weeks (visit 1 to visit 12), until index ulcer healing, death, or lost to follow-up (whichever came first). These patients were then followed up 12 weeks later to determine the longer term outcome of the wound (healed, recurrence, remained unhealed). The itemized costs derived from the medical service were retrieved from the relevant departments of the study sites. The patients' health-related quality of life was assessed at baseline and the last visit of the 12-week follow-up period (or until index ulcer healing), using the official Singapore version of the EuroQol five-dimension-5L questionnaire, which also includes a visual analog scale (EQ-VAS).

RESULTS

A total of 116 patients were enrolled; 63% were men, and the mean patient age was 64.7 years. Of the 116 patients, 85 (73%) had a healed ulcer at 24 weeks (mean duration to ulcer healing, 49 days), and 11 (12.9%) had experienced ulcer recurrence within the study period. Within the 6-month follow-up period, the mean direct healthcare cost per patient was USD$1998. The patients with healed ulcers had significantly lower costs per patient compared with those with unhealed ulcers (USD$1713 vs USD$2780). Regarding health-related quality of life, 71% of the patients had a lower quality of life at baseline, which had improved at 12 weeks of follow-up, with only 58% of the patients reported to have a lower quality of life. Also, the patients with healed ulcers scored higher for both utilities (societal preference weights) and EQ-VAS at follow-up (P < .001). In contrast, patients with unhealed ulcers only scored higher EQ-VAS at follow-up (P = .003).

CONCLUSIONS

The findings from this exploratory study provide information on the clinical, quality of life, and economic burden of VLUs in an Asian population and suggest the importance of healing VLUs to reduce the effects on patients. The present study provides data as a basis for economic evaluation as a consideration for the treatment of VLUs.

Validating the Well-Being of Older People (WOOP) Instrument in China

Generic health-related quality of life (HRQoL) measures have been used for estimating utility value, which is then used for calculating quality-adjusted life years (QALYs). HRQoL measures may not capture many of the relevant and important non-health aspects of quality of life. The well-being of older people (WOOP) instrument was first developed in the Netherlands. This study aimed to validate this new instrument among older people in China. WOOP was first translated into simplified Chinese (for use in Mainland China) by two experienced translators. From July to August 2022, a cross-sectional study was conducted on a convenience sample of 500 older people in Southwestern China. Older people who provided consent reported their demographic information and completed the simplified Chinese version of the WOOP instrument using a pencil and paper. The feasibility of WOOP was determined by the percentage of missing responses. Then, using the data without any missing responses, we examined the item response distributions, pairwise Spearman correlations, underlying factors, and known-group validity of WOOP. Among the nine items of WOOP, three had more than 10% missing responses. The response distributions of the nine items were overall good without signs of ceiling and floor effects. The correlations among the WOOP items were low. A two-factor exploratory factor analysis model suggested that the WOOP items can be categorized into either internal or external well-being items. Good known-group validity results were found. Some WOOP items may not be easily understood by a small proportion of rural residents. However, other results have suggested WOOP to be a valid instrument for measuring the well-being of the elderly in China. The availability of WOOP enables the measurement of well-being-related utility.

Conceptual Framework for Optimised Proxy Value Set Selection Through Supra-National Value Set Development for the EQ-5D Instruments

BACKGROUND

Preference differences between countries and populations justify the use of country-specific value sets for the EQ-5D instruments. There are no clear criteria based on which the selection of value sets for countries without a national value set should be made. As part of the European PECUNIA project, this study aimed to identify factors contributing to differences in preference-based valuations and develop supra-national value sets for homogenous country clusters in Europe.

METHODS

A literature review was conducted to identify factors relevant to variations in the EQ-5D-3L/5L health state valuations across countries. Factors fulfilling the pre-specified criteria of validity, reliability, international feasibility and comparability were used to group 27 European Union member states, the European Free Trade Association countries and the UK. Clusters of countries were developed based on the frequency of their appearance in the same grouping. The supra-national value sets were estimated for these clusters from the coefficients of existing published valuation studies using the ordinary least-squares model.

RESULTS

Ten factors were identified from 69 studies. From these, five grouping variables: (1) culture and religion; (2) linguistics; (3) healthcare system typology; (4) healthcare system financing; and (5) sociodemographic aspects were derived to define the groups of homogenous countries. Frequency-based grouping revealed five cohesive clusters: English-speaking, Nordic, Central-Western, Southern and Eastern European.

CONCLUSIONS

European countries were clustered considering variables that may relate to differences in health state valuations. Supra-national value sets provide optimised proxy value set selection in the lack of a national value set and/or for regional decision making.

Feasibility and validity of the EQ-5D-3L in the elderly Europeans: a secondary data analysis using SHARE(d) data

PURPOSE

To determine feasibility and validity of the EQ-5D-3L in the elderly European population.

METHODS

Secondary data analysis based on the study of health, ageing, and retirement in Europe (SHARE) to determine the percentage of missing items for EQ-5D dimensions and EQ VAS, and to demonstrate convergent/divergent validity with measures included in the SHARE survey. Known-groups validity was tested using literature-based hypotheses. Correlation coefficients and Cohen's f are reported.

RESULTS

Missing values were below 3% across all EQ-5D dimensions and gender strata, slightly increasing with age. Individuals' responses to each EQ-5D dimension were related to their ratings of other measures in expected directions. The EQ VAS and all EQ-5D dimensions (except anxiety/depression) moderately to strongly correlated with physical [e.g. number of limitations in activities of daily living (ADL): r = 0.313-0.658] and generic measures [CASP (control, autonomy, self-realization, pleasure)-19 scale, self-perceived health, number of symptoms: r = 0.318-0.622], while anxiety/depression strongly correlated with the EURO-D scale (r = 0.527). Both EQ-5D dimensions and EQ VAS discriminated well between two [or more] groups known to differ [e.g. anxiety/depression discriminated well between persons classified as depressed/not depressed using the EURO-D scale, f = 0.51; self-care differentiated best between individuals without and with 1 + ADL limitations, f = 0.69]. Sociodemographic variables like gender, education, and partner in household were hardly associated with EQ VAS scores (f < 0.25).

CONCLUSION

With item non-response of less than 3%, good discriminatory, and construct properties, the EQ-5D-3L showed to be a feasible and valid measure in the elderly Europeans.

Investigating 5-Level EQ-5D (EQ-5D-5L) Values Based on Preferences of Patients With Heart Disease

OBJECTIVES

Several studies have shown that patients with heart disease value hypothetical health states differently from the general population. We aimed to investigate the health preferences of patients with heart disease and develop a value set for the 5-level EQ-5D (EQ-5D-5L) based on these patient preferences.

METHODS

Patients with confirmed heart disease were recruited from 2 hospitals in Singapore. A total of 86 EQ-5D-5L health states (10 per patient) were valued using a composite time trade-off method according to the international valuation protocol for EQ-5D-5L; 20-parameter linear models and 8-parameter cross-attribute level effects models with and without an N45 term (indicating whether any health state dimension at level 4 or 5 existed) were estimated. Each model included patient-specific random intercepts. Model performance was evaluated for out-of-sample and in-sample predictive accuracy in terms of root mean square error. The discriminative ability of the utility values was assessed using heart disease-related functional classes.

RESULTS

A total of 576 patients were included in the analysis. The preferred model, with the lowest out-of-sample root mean square error, was a 20-parameter linear model including N45. Predicted utility values ranged from -0.727 for the worst state to 1 for full health; the value for the second-best state was 0.981. Utility values demonstrated good discriminative ability in differentiating among patients of varied functional classes.

CONCLUSIONS

An EQ-5D-5L value set representing the preferences of patients with heart disease was developed. The value set could be used for patient-centric economic evaluation and health-related quality of life assessment for patients with heart disease.

Psychometric properties of the EQ-5D-5L: a systematic review of the literature

PURPOSE

Although the EQ-5D has a long history of use in a wide range of populations, the newer five-level version (EQ-5D-5L) has not yet had such extensive experience. This systematic review summarizes the available published scientific evidence on the psychometric properties of the EQ-5D-5L.

METHODS

Pre-determined key words and exclusion criteria were used to systematically search publications from 2011 to 2019. Information on study characteristics and psychometric properties were extracted: specifically, EQ-5D-5L distribution (including ceiling and floor), missing values, reliability (test-retest), validity (convergent, known-groups, discriminate) and responsiveness (distribution, anchor-based). EQ-5D-5L index value means, ceiling and correlation coefficients (convergent validity) were pooled across the studies using random-effects models.

RESULTS

Of the 889 identified publications, 99 were included for review, representing 32 countries. Musculoskeletal/orthopedic problems and cancer (n = 8 each) were most often studied. Most papers found missing values (17 of 17 papers) and floor effects (43 of 48 papers) to be unproblematic. While the index was found to be reliable (9 of 9 papers), individual dimensions exhibited instability over time. Index values and dimensions demonstrated moderate to strong correlations with global health measures, other multi-attribute utility instruments, physical/functional health, pain, activities of daily living, and clinical/biological measures. The instrument was not correlated with life satisfaction and cognition/communication measures. Responsiveness was addressed by 15 studies, finding moderate effect sizes when confined to studied subgroups with improvements in health.

CONCLUSIONS

The EQ-5D-5L exhibits excellent psychometric properties across a broad range of populations, conditions and settings. Rigorous exploration of its responsiveness is needed.

Psychometric performance assessment of Malay and Malaysian English version of EQ-5D-5L in the Malaysian population

PURPOSE

To determine the psychometric properties and performance of Malay and English versions of the EQ-5D-5L descriptive instrument in the general Malaysian population.

METHODS

1137 members of the Malaysian general public were sampled in this national study. Respondents were recruited by quota sampling of urbanicity, gender, age, and ethnicity. In face-to-face interviews, respondents first answered the EQ-5D-5L questionnaire administered using the EQ-Valuation Technology software, and then completed the EQ-5D-3L questionnaire on paper. A subgroup of the respondents were given paper form of EQ-5D-5L for completion within 2 weeks for test-retest reliability. Ceiling effects, response redistribution, informativity, and convergent validity were compared between EQ-5D-5L and ED-5D-3L separately by Malay and English language versions.

RESULTS

The proportion of 'full health' responses (11111) drastically decreased by 25.55% and 15.74% in the Malay and English language versions indicating lower ceiling effects in EQ-5D-5L. Inconsistencies from response redistribution was below 6% for all dimensions across languages. The measure of relative informativity was comparatively higher in EQ-5D-5L than in EQ-5D-3L in both language versions, with the exception of dimensions mobility and pain/discomfort in the English version. Convergent validity in terms of correlation with EQ-VAS was relatively better for EQ-5D-5L dimensions, with pain/discomfort of the Malay version having the strongest correlation (|r| = 0.37). Also, reliability testing revealed moderate to poor agreements on all 5L dimensions.

CONCLUSIONS

EQ-5D-5L fared better in terms of psychometric performance compared to EQ-5D-3L for both language versions. This encourages the application of the EQ-5D-5L in health-related research in Malaysia.

An exploration of differences between Japan and two European countries in the self-reporting and valuation of pain and discomfort on the EQ-5D

PURPOSE

To investigate the systematic differences in the self-reporting and valuation of overall health and, in particular, pain/discomfort between three countries (England/UK, Japan, and Spain) on the EQ-5D.

METHODS

Existing datasets were used to explore differences in responses on the EQ-5D descriptive system between Japan (3L and 5L), the UK (3L), England (5L), and Spain (5L), particularly on the dimension of pain/discomfort. The role of different EQ dimensions in determining self-reported overall health scores for the EuroQol visual analog scale (EQ-VAS) was investigated using ordinary least squares regression. Time trade-off (TTO) results from Japanese and UK respondents for the EQ-5D-3L as well as Japanese and English respondents for the EQ-5D-5L were compared using t tests.

RESULTS

For the EQ-5D-3L, a higher percentage of respondents in Japan than in the UK reported 'no pain/discomfort' (81.6 vs 67.0%, respectively); for the EQ-5D-5L, the proportions were 79.2% in Spain, 73.2% in Japan, and 63-64% in England, after adjusting for age differences in samples. The 'pain/discomfort' dimension had the largest impact on respondents' self-reported EQ-VAS only for EQ-5D-3L in Japan. Using the EQ-5D-3L, Japanese respondents were considerably less willing to trade off time to avoid pain/discomfort than the UK respondents; for example, moving from health state, 11121 (some problems with pain/discomfort) to 11131 (extreme pain/discomfort) represented a decrement of 0.65 on the observed TTO value in the UK compared with 0.15 in Japan. Using the EQ-5D-5L, Japanese respondents were also less willing to trade off time to avoid pain/discomfort than respondents in England; however, the difference in values was much smaller than that observed using EQ-5D-3L data.

CONCLUSIONS

This study provides evidence of between-country differences in the self-reporting and valuation of health, including pain/discomfort, when using EQ-5D in general population samples. The results suggest a need for caution when comparing or aggregating EQ-5D self-reported data in multi-country studies.

Less Is More: Cross-Validation Testing of Simplified Nonlinear Regression Model Specifications for EQ-5D-5L Health State Values

BACKGROUND

The conventional method for modeling of the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) health state values in national valuation studies is an additive 20-parameter main-effects regression model. Statistical models with many parameters are at increased risk of overfitting-fitting to noise and measurement error, rather than the underlying relationship.

OBJECTIVES

To compare the 20-parameter main-effects model to simplified, nonlinear, multiplicative regression models in terms of how accurately they predict mean values of out-of-sample health states.

METHODS

We used data from the Spanish, Singaporean, and Chinese EQ-5D-5L valuation studies. Four models were compared: an 8-parameter model with single parameter per dimension, multiplied by cross-dimensional parameters for levels 2, 3, and 4; 9- and 11-parameter extensions with handling of differences in the wording of level 5; and the "standard" additive 20-parameter model. Fixed- and random-intercept variants of all models were tested using two cross-validation methods: leave-one-out at the level of valued health states, and of health state blocks used in EQ-5D-5L valuation studies. Mean absolute error, Lin concordance correlation coefficient, and Pearson R between observed health state means and out-of-sample predictions were compared.

RESULTS

Predictive accuracy was generally best using random intercepts. The 8-, 9-, and 11-parameter models outperformed the 20-parameter model in predicting out-of-sample health states.

CONCLUSIONS

Simplified nonlinear regression models look promising and should be investigated further using other EQ-5D-5L data sets. To reduce the risk of overfitting, cross-validation is recommended to inform model selection in future EQ-5D valuation studies.