A Validation Study of the EQ-5D-5L and ICEpop Capability Measure for Older People Among Older Individuals With Depressive Symptoms in Brazil

OBJECTIVES

This study aimed to assess the known-groups validity of the EQ-5D-5L and the ICEpop Capability Measure for Older People (ICECAP-O), 2 outcome measures used in economic evaluation, among older adults with depressive symptoms in socioeconomically deprived areas of Brazil. We also explored the role of education and income on responses to these measures.

METHODS

This cross-sectional study used baseline data from PROACTIVE, a cluster randomized controlled trial to evaluate a psychosocial intervention for late-life depression among older adults. Participants aged ≥60 years with a 9-item Patient Health Questionnaire score ≥10 were recruited from 20 primary healthcare clinics. Ordered logistic regression models assessed the association between depressive symptoms severity, income, and education and dimension-level responses on the EQ-5D-5L and ICECAP-O. Multivariable regression models investigated the ability of EQ-5D-5L and ICECAP-O scores to discriminate between depressive symptoms severity levels and other characteristics, including education level and household income.

RESULTS

A total of 715 participants were included in the study. Depressive symptoms severity was associated with all EQ-5D-5L and ICECAP-O dimensions, except the ICECAP-O enjoyment attribute. In contrast, household income was only associated with the ICECAP-O security attribute. Higher severity of depressive symptoms (9-item Patient Health Questionnaire scores) was also strongly associated with lower (ie, worse) scores on both measures in all models. Education level and household income showed no association with either EQ-5D-5L or ICECAP-O scores.

CONCLUSIONS

To best of our knowledge, this is the first study that investigated the validity of these 2 measures among older adults in Brazil. Both EQ-5D-5L and ICECAP-O showed evidence of validity in differentiating depressive symptom severity.

Comparing the measurement properties of the ICECAP-A and ICECAP-O instruments in ages 50-70: a cross-sectional study on a representative sample of the Hungarian general population

OBJECTIVE

The ICECAP-A and ICECAP-O were validated as capability wellbeing measures of adults aged 18 + and 65 + years, respectively. We aimed to compare their measurement properties in age group 50-70.

METHODS

Data were derived from a cross-sectional survey among a sample representative for the adult Hungarian population. Respondents aged between 50 and 70 filled in both the ICECAP-A and ICECAP-O questionnaires. We assessed and compared feasibility, agreement, discriminatory power, convergent and content validity of the two instruments and explored the determinants of the differences between the two measures.

RESULTS

707 respondents (99.4%) provided full answers to both questionnaires (46.3% women, average age 60.1 years). The instruments showed similar construct and convergent validity and discriminatory power. Pearson-correlations between instrument items were strong (r > 0.5). ICECAP-A and ICECAP-O scores could be calculated from each other with a good confidence (R² = 0.69 and 0.71). ICECAP-O scores (mean 0.87, SD = 0.12) were systematically higher than ICECAP-A scores (0.85, SD = 0.15) in most subgroups. The difference increased with the deterioration of capability and health, and with age. Regression results showed that employment and health status had larger marginal effect on the ICECAP-A than on the ICECAP-O scores, and these effects were larger than the effect of age on both measures.

CONCLUSION

Validity of both instruments was confirmed in the age groups 50-70. Given that employment and health status are important determinants of the differences between the two instruments besides age, the possibility of linking the choice between ICECAP-A and ICECAP-O to these factors should be investigated by further research.

Musculoskeletal health and capability wellbeing: Associations between the HAQ-DI, ICECAP-A and ICECAP-O measures in a population survey

BACKGROUND

The capability approach has received increasing attention in wellbeing measurement in the past years, but it has still remained an underexplored area in musculoskeletal (MSK) health.

OBJECTIVE

We aimed to explore the capability wellbeing in relation to MSK health, by measuring the associations between the Health Assessment Questionnaire Disability Index (HAQ-DI) physical functioning and the ICECAP-A and ICECAP-O capability wellbeing measures.

DESIGN

A cross-sectional survey was performed in 2019 on a representative sample of the Hungarian general adult population.

METHOD

Capability wellbeing was measured by the ICECAP-A (age-group 18-64) and ICECAP-O (age group 65+) questionnaires. MSK health was defined by the HAQ-DI, the mobility domain of the EQ-5D-3L/-5L health status measures, self-reported walking problems and MSK diagnosis (neck/back/low back defects, hip/knee arthrosis, osteoporosis).

RESULTS

Altogether 2021 individuals (female: 50.1%) participated in the survey with mean (SD) age of 48.7 (17.9) years and HAQ-DI of 0.138 (0.390). ICECAP-A (N = 1568, 77.6%) and ICECAP-O (N = 453, 22.4%) scores were on average (SD) 0.894 (0.126) and 0.828 (0.150), respectively. Spearman correlations between the HAQ-DI and ICECAP-A/-O index scores were moderate (r = -0.303 and -0.496; p < 0.05). Both the ICECAP-A/-O index scores differed significantly (ANOVA test, p < 0.05) across all MSK subgroups. In the ordinary least square regressions, marginal effects of ICECAP-A/-O scores on HAQ-DI were significant (-0.149 and -0.123) when controlling for socio-demographic characteristics.

CONCLUSIONS

MSK health problems are associated with lower capability wellbeing. ICECAP-A/-O might capture effects of MSK conditions not measured by the HAQ-DI or the EQ-5D-5L. Further studies should test these associations in disease-specific samples.

Self- and proxy-rating of the ICECAP-O for people with dementia: A cross-sectional linguistic validation study in Germany and Portugal

BACKGROUND

The capability concept became a recognized approach to the measurement of quality of life. The ICECAP-O for older people aims to measure capabilities and has recently been used in people with dementia (self-rating) and informal carers (substituted judgement). However, linguistic validation studies have so far been lacking.

METHODS

A cross-sectional cognitive interview study with 15 people with dementia (PwD) and 23 informal carers (ICs) was conducted in Germany and Portugal. Respondents were asked to reveal their understanding of the ICECAP-O and the capability approach as well as the response process. A summarising content analysis was performed.

RESULTS

Despite the small sample, our linguistic validation of the German and Portuguese translations detected considerable difficulties or deviations in item comprehension when compared with the intended meaning. In some cases, the item interpretations did not reflect the entire scope of the associated capability dimension, though they were basically correct. Moreover, participants were not able to differentiate some items appropriately from one another, and some misinterpretations occurred. ICs relied mainly on observable behaviour, emotions, or verbal expressions of the PwD. Therefore, ICs found items that ask about the achievement of individual expectations or thoughts about the future difficult to assess. Only very few PwD clearly indicated that they understood the capability approach. ICs in Germany had more difficulties in understanding the capability concept than in ICs Portugal.

DISCUSSION

This linguistic validation study in Germany and Portugal indicates a need for some rephrasing and refinements of the ICECAP-O translated items in both countries to fully encompass some dimensions and avoid misinterpretations. Further studies with larger samples are necessary. Based on our findings, the current German version for ICs' substituted judgement cannot be recommended for this kind of respondents without further advancements.

Measuring capability wellbeing in adults at different stages of life for use in economic evaluation of health and care interventions: a qualitative investigation in people requiring kidney care

PURPOSE

Capability wellbeing measures, such as the ICECAP measures, have been proposed for use in economic evaluations to capture broader outcomes of health and care interventions. The ICECAP measures have been developed to reflect capabilities at different stages of life. Some patient groups include patients of different ages and at different stages of life, so it is not always apparent which ICECAP measure is most relevant. This study explores the impact of age and life stage on completion, where both ICECAP-A and ICECAP-O were completed by the same patient.

METHODS

A think-aloud study, and an associated semi-structured interview were conducted with people receiving kidney care as a renal outpatient, kidney transplant outpatient, or through receiving facility-based haemodialysis. Qualitative analysis focused on (1) differences in responses across measures by individuals, where attributes had conceptual overlap, (2) key factors in self-reported capability levels, and (3) measure preference.

RESULTS

Thirty participants were included in the study, with a mix of older and younger adults. Attributes with similar wording across measures produced similar responses compared to attributes where wording differed. Age and health were key factors for self-reported capability levels. ICECAP-A was slightly preferred overall, including by older adults.

CONCLUSION

This study suggests use of ICECAP-A in patients with certain chronic health conditions that include a mix of adults across the life course. This study highlights the importance of considering the stage of life when using capability measures and in economic evaluations of health and care interventions more generally.

Capability of well-being: validation of the Hungarian version of the ICECAP-A and ICECAP-O questionnaires and population normative data

Purpose

We aimed to develop and assess the psychometric characteristics of the Hungarian language version of two well-being capability measures, the ICEpop CAPability measure for Adults/Older people (ICECAP-A/-O), and to establish population norms.

Methods

A cross-sectional survey was performed involving a representative sample of the Hungarian population. Socio-demographic characteristics, the use and provision of informal care were recorded. The Minimum European Health Module (MEHM), EQ-5D-5L, WHO-5 well-being index, happiness and life satisfaction visual analogue scale (VAS), Satisfaction with Life Scale (SWLS) measures were applied alongside the ICECAP-A (age-group 18–64) and ICECAP-O (age-group 65+).

Results

Altogether 1568 and 453 individuals completed the ICECAP-A/-O questionnaires, respectively. Cronbach’s alpha was 0.86 for both measures (internal consistency). Subgroup analyses showed positive associations between ICECAP-A/-O scores and marital status, employment, income, health status (MEHM) and informal care use (construct validity). Pearson correlations were strong (r > 0.5; p < 0.01) between ICECAP-A/-O indexes and EQ-5D-5L, WHO-5, happiness and satisfaction VAS and SWLS scores (convergent validity). The age, education, and marital status were no longer significant in the multiple regression analysis. Test–retest average (SD) scores were 0.88 (0.11) and 0.89 (0.10) for the ICECAP-A, and equally 0.86 (0.09) for the ICECAP-O (reliability).

Conclusion

This is the first study to provide ICECAP-A/-O population norms. Also, it is the first to explore associations with WHO-5 well-being index which, alongside the MEHM measures, enable estimates from routinely collected international health statistics. The Hungarian ICECAP-A/-O proved to be valid and reliable measurement tools. Socio-demographic characteristics had minor or no impact on ICECAP-A/-O. Other influencing factors deserve further investigation in future research.

Electronic supplementary material

The online version of this article (10.1007/s11136-020-02542-1) contains supplementary material, which is available to authorized users.

Assessing the construct validity and responsiveness of Preference-Based Measures (PBMs) in cataract surgery patients

PURPOSE

The validity and responsiveness of the EQ-5D-3L in visual conditions has been questioned, inspiring development of a vision 'bolt-on' domain (EQ-5D-3L + VIS). Developments in preference-based measures (PBM) also includes the EQ-5D-5L and the ICECAP-O capability wellbeing measure. This study aimed to examine the construct validity and responsiveness of the EQ-5D-3L, EQ-5D-5L, EQ-5D-3L + VIS and ICECAP-O in cataract surgery patients for the first time, to inform choice of PBM for economic evaluation in this population.

METHODS

The analyses used data from the UK Predict-CAT cataract surgery cohort study. PBMs and the Cat-PROM5 [a validated measure of cataract quality of life (QOL)] were completed before surgery and 4-8 weeks after. Construct validity was assessed using correlations and known-group differences evaluated using regression. Responsiveness was evaluated using effect sizes and analysis of variance to compare change scores between groups, defined by patient-reported and clinical outcomes.

RESULTS

The sample comprised 1315 patients at baseline. No PBMs were associated with visual acuity and only the ICECAP-O (Spearman's rs =  - 0.35), EQ-5D-3L + VIS (rs =  - 0.42) and EQ-5D-5L (Value Set for England rs =  - 0.31) correlated at least moderately with the Cat-PROM5. Effect sizes of change were consistently largest for the EQ-5D-3L + VIS (range 0.34-0.41), followed by the ICECAP-O (range 0.20-0.34). Results indicated no improvement in responsiveness using the EQ-5D-5L (range 0.13-0.16) compared to the EQ-5D-3L (range 0.17-0.20).

CONCLUSIONS

Whilst no PBMs comprehensively demonstrated evidence of construct validity and responsiveness in cataract surgery patients, the ICECAP-O was the most responsive generic PBM to improvements in QOL. Surprisingly the EQ-5D-5L was not more responsive than the EQ-5D-3L in this setting.

A validation study of the ICECAP-O in informal carers of people with dementia from eight European Countries

PURPOSE

The pressure on healthcare budgets remains high, partially due to the ageing population. Economic evaluation can be a helpful tool to inform resource allocation in publicly financed systems. Such evaluations frequently use health-related outcome measures. However, in areas such as care of older people, improving health outcomes is not necessarily the main focus of care interventions and broader outcome measures, including outcomes for those providing informal care, may be preferred when evaluating such interventions. This paper validates a recently introduced well-being measure, the ICECAP-O, in a population of informal carers for people with dementia from eight European countries.

METHODS

Convergent and discriminant validity tests were performed to validate the ICECAP-O using data obtained in a sample of 451 respondents from Germany, Ireland, Italy, the Netherlands, Norway, Portugal, Sweden and the UK. These respondents completed a number of standardized questionnaires within the framework of the Actifcare project.

RESULTS

The ICECAP-O performed well among informal carers, in terms of both convergent and discriminant validity. In the multivariate analysis, it was found to be significantly associated with the age of the person with dementia, EQ-5D-5L health problem index of the person with dementia, carer-patient relationship, care recipient CDR, carer LSNS Score, the PAI score, and Perseverance Time.

CONCLUSION

The ICECAP-O appears to be a valid measure of well-being in informal carers for people with dementia. The ICECAP-O may therefore be useful as an outcome measure in economic evaluations of interventions aimed at such informal carers, when these aim to improve well-being beyond health.

ICECAP-O, the current state of play: a systematic review of studies reporting the psychometric properties and use of the instrument over the decade since its publication

PURPOSE

A paper reporting the development of the ICECAP-O was published in 2006. Since then, there has been increasing interest in the use of capability-based measures within health economics and the ICECAP-O has been suggested for use in economic evaluation by decision-making bodies in the Netherlands and UK.

METHODS

A systematic review of studies published between January 2006 and October 2018 which have assessed the psychometric properties of ICECAP-O or utilised the measure within economic evaluation.

RESULTS

Twenty-four studies explored the psychometric properties of ICECAP-O and 21 have utilised the measure within economic evaluation; one study reported psychometric properties as well as utilising the measure within economic evaluation. The ICECAP-O has good construct validity and responsiveness, but there is evidence of some issues relating to content validity. In the context of economic evaluation, the ICECAP-O has, to date, mainly been included as a secondary economic measure and the reporting of results is brief with minimal detail and often no discussion. Five of the economic evaluation studies combined scores from ICECAP-O with time, but each used different terminology to describe this result.

CONCLUSION

Focus, in terms of publications, appears to have shifted now from assessment of psychometric properties to the utilisation of the ICECAP-O within economic evaluation. Further research is needed with respect to a decision-rule for the ICECAP measures. This additional research should also guide users in terms of appropriate analysis, terminology and presentation of results, which are in-keeping with the conceptual framework underpinning the ICECAP-O.

A cost-effectiveness study of ICT training among the visually impaired in the Netherlands

BACKGROUND

Due to the ageing population, the number of visually impaired people in the Netherlands will increase. To ensure the future availability of services in rehabilitative eye care, we aim to assess the cost-effectiveness of information and communication technology (ICT) training among visually impaired adults from a societal perspective, using primary data from two large rehabilitative eye care providers in the Netherlands.

METHODS

Participants were asked to fill in a questionnaire, which used six different instruments at three different time points: pre training, post training and three months post training. We investigated whether the participants' quality of life and well-being improved after the training and whether this improvement persisted three months post training. Economic evaluation was conducted by comparing costs and outcomes before and after training. Quality of life and well-being were derived from the EQ-5D and ICECAP-O, respectively. Costs for productivity losses and medical consumption were obtained from the questionnaires. Information regarding the costs of training sessions was provided by the providers.

RESULTS

Thirty-eight participants filled in all three questionnaires. The mean age at baseline was 63 years (SD = 16). The effect of ICT training on ICT skills and participants' well-being was positive and persisted three months after the last training session. Assuming these effects remain constant for 10 years, this would result in an incremental cost-effectiveness ratio (ICER) of € 11,000 per quality-adjusted life-year (QALY) and € 8000 per year of well-being gained, when only the costs of ICT training are considered. When the total costs of medical consumption are included, the ICER increases to € 17,000 per QALY gained and € 12,000 per year of well-being gained. Furthermore, when the willingness-to-pay threshold is € 20,000 per year of well-being, the probability that ICT training will be cost-effective is 75% (91% when including only the costs of ICT training).

CONCLUSION

Our study suggests that ICT training among the visually impaired is cost-effective when the effects of ICT training on well-being persist for several years. However, further research involving a larger sample and incorporating long-term effects should be conducted.

Quantifying the Relationship between Capability and Health in Older People: Can't Map, Won't Map

BACKGROUND

Intuitively, health and capability are distinct but linked concepts. This study aimed to quantify the link between a measure of health status (EQ-5D-3L) and capability (ICECAP-O) using regression-based methods.

METHODS

EQ-5D-3L and ICECAP-O data were collected from a sample of older people ( n = 584), aged over 65 years, requiring a hospital visit and/or care home resident, and recruited to one of 3 studies forming the Medical Crisis in Older People (MCOP) program in England. The link of EQ-5D-3L with 1) ICECAP-O tariff scores were estimated using ordinary least squares (OLS) or censored least absolute deviation (CLAD) regression models; and 2) ICECAP-O domain scores was estimated using multinomial logistic (MNL) regression. Mean absolute error (MAE), root mean squared error (RMSE), absolute difference (AD) between mean observed and estimated values, and the R² statistic were used to judge model performance.

RESULTS

In this sample of older people ( n = 584), higher scores on the EQ-5D-3L were shown to be linked with higher ICECAP-O scores when using linear regression. An OLS-regression model was identified to be the best performing model with the lowest error statistics (AD = 0.0000; MAE = 0.1208; MSE = 0.1626) and highest goodness of fit ( R² = 0.3532); model performance was poor when predicting the lower ICECAP-O tariff scores. The three domains of the EQ-5D-3L showing a statistically significant quantifiable link with the ICECAP-O tariff score were self-care, usual activities, and anxiety/depression.

CONCLUSION

A quantifiable, but weak, link between health (EQ-5D-3L) and capability (ICECAP-O) was identified. The findings from this study add further support that the ICECAP-O is providing complimentary information to the EQ-5D-3L. Mapping between the 2 measures is not advisable and the measures should not be used as direct substitutes to capture the impact of interventions in economic evaluations.

Outcome assessment after hip fracture: is EQ-5D the answer?

Objectives

To study the measurement properties of a joint specific patient reported outcome measure, a measure of capability and a general health-related quality of life (HRQOL) tool in a large cohort of patients with a hip fracture.

Methods

Responsiveness and associations between the Oxford Hip Score (a hip specific measure: OHS), ICEpop CAPability (a measure of capability in older people: ICECAP-O) and EuroQol EQ-5D (general health-related quality of life measure: EQ-5D) were assessed using data available from two large prospective studies. The three outcome measures were assessed concurrently at a number of fixed follow-up time-points in a consecutive sequence of patients, allowing direct assessment of change from baseline, inter-measure associations and validity using a range of statistical methods.

Results

ICECAP-O was not responsive to change. EQ-5D was responsive to change from baseline, with an estimated standardised effect size for the two datasets of 0.676 and 0.644 at six weeks and four weeks respectively; this was almost as responsive to change as OHS (1.14 at four weeks). EQ-5D correlated strongly with OHS; Pearson correlation coefficients were 0.74, 0.77 and 0.70 at baseline, four weeks and four months. EQ-5D is a moderately good predictor of death at 12 months following hip fracture. Furthermore, EQ-5D reported by proxies (relatives and carers) behaves similarly to self-reported scores.

Conclusions

Our findings suggest that a general HRQOL tool such as EQ-5D could be used to measure outcome for patients recovering from hip fracture, including those with cognitive impairment.

Cite this article: Bone Joint Res 2014;3:69–75.