A Systematic Review of the Feasibility and Psychometric Properties of the ICEpop CAPability Measure for Adults and Its Use So Far in Economic Evaluation

From Health to Well-Being: Toward a Monetary Valuation of a Well-Being-Adjusted Life-Year

OBJECTIVES

Economic evaluations using broader measures to capture benefits beyond improved health can inform policy making, but only if the monetary value of gains measured using these instruments is understood. This study explored contingent valuation as a method to estimate the monetary value of a well-being-adjusted life-year (WALY) as measured by ICEpop Capability Measure for Adults (ICECAP-A).

METHODS

In a large online survey of representative samples from 7 European countries, participants valued a change in the ICECAP-A from their current health state to a randomly assigned hypothetical state. Participants were instructed that an unspecified treatment could avoid a loss or produce a gain in well-being and were asked for their willingness to pay (WTP) for this treatment. WTP per WALY was calculated using an aggregated approach that used ICECAP-A tariffs from the United Kingdom.

RESULTS

We analyzed a sample of 7428 observations, focusing on avoided losses (n = 6002) because the results for gains were not theoretically valid. Different cutoff points for a marginal change were explored. Depending on the definition of a marginal change, WTP per WALY averaged between €13 323.28 and €61 375.63 for avoided losses between [0, 0.5] and [0, 0.1], respectively, for 1 month. Mean WTP per WALY varied across the countries as follows: Denmark (€17 867.93-€88 634.14), France (€10 278.35-€45 581.28), Germany (€12 119.39-€54 566.56), Italy (€11 753.69-€52 161.25), The Netherlands (€14 612.88-€58 951.74), Spain (€11 904.12-€57 909.17), and United Kingdom (€13 133.75-€68 455.85).

CONCLUSION

Despite the inherent limitations of our study, it offers valuable insights into methods for eliciting the WTP for changes in capability well-being as measured with ICECAP-A.

An exploratory randomised trial investigating feasibility, potential impact and cost effectiveness of link workers for people living with multimorbidity attending general practices in deprived urban communities

BACKGROUND

Social prescribing link workers are non-health or social care professionals who connect people with psychosocial needs to non-clinical community supports. They are being implemented widely, but there is limited evidence for appropriate target populations or cost effectiveness. This study aimed to explore the feasibility, potential impact on health outcomes and cost effectiveness of practice-based link workers for people with multimorbidity living in deprived urban communities.

METHODS

A pragmatic exploratory randomised trial with wait-list usual care control and blinding at analysis was conducted during the COVID 19 pandemic (July 2020 to January 2021). Participants had two or more ongoing health conditions, attended a general practitioner (GP) serving a deprived urban community who felt they may benefit from a one-month practice-based social prescribing link worker intervention.. Feasibility measures were recruitment and retention of participants, practices and link workers, and completion of outcome data. Primary outcomes at one month were health-related quality of life (EQ-5D-5L) and mental health (HADS). Potential cost effectiveness from the health service perspective was evaluated using quality adjusted life years (QALYs), based on conversion of the EQ-5D-5L and ICECAP-A capability index to utility scoring.

RESULTS

From a target of 600, 251 patients were recruited across 13 general practices. Randomisation to intervention (n = 123) and control (n = 117) was after baseline data collection. Participant retention at one month was 80%. All practices and link workers (n = 10) were retained for the trial period. Data completion for primary outcomes was 75%. There were no significant differences identified using mixed effects regression analysis in EQ-5D-5L (MD 0.01, 95% CI -0.07 to 0.09) or HADS (MD 0.05, 95% CI -0.63 to 0.73), and no cost effectiveness advantages. A sensitivity analysis that considered link workers operating at full capacity in a non-pandemic setting, indicated the probability of effectiveness at the €45,000 ICER threshold value for Ireland was 0.787 using the ICECAP-A capability index.

CONCLUSIONS

While the trial under-recruited participants mainly due to COVID-19 restrictions, it demonstrates that robust evaluations and cost utility analyses are possible. Further evaluations are required to establish cost effectiveness and should consider using the ICE-CAP-A wellbeing measure for cost utility analysis.

REGISTRATION

This trial is registered on ISRCTN.

TITLE

Use of link workers to provide social prescribing and health and social care coordination for people with complex multimorbidity in socially deprived areas.

TRIAL ID

ISRCTN10287737. Date registered 10/12/2019. Link: https://www.isrctn.com/ISRCTN10287737.

Exploring the measurement of health related quality of life and broader instruments: A dimensionality analysis

BACKGROUND

Comprehensively measuring the outcomes of interventions and policy programmes impacting both health and broader areas of quality of life (QoL) is important for decision-making within and across sectors. Increasingly, broad QoL measures are being developed to capture outcomes beyond health-related quality of life (HRQoL). Jointly exploring the dimensionality of diverse instruments can improve our understanding about their evaluative space and how they conceptually build on each other. This study explored the measurement relationship between five broader QoL measures and the most widely used HRQoL measure, the EQ-5D.

METHODS

Participants from the Dutch general population (n = 1002) completed six instruments (n = 126 items) in December of 2020. The measurement relationship was explored using qualitative and quantitative dimensionality assessment methods. This included a content analysis and exploratory factor analyses which were used to develop a confirmatory factor model of the broader QoL dimensions. Correlations between the identified dimensions and self-reported overall health and wellbeing were also explored.

RESULTS

The final CFA model exhibited acceptable/good fit and described 12 QoL dimensions: 'psychological symptoms', 'social relations', 'physical functioning', 'emotional resilience', 'pain', 'cognition', 'financial needs', 'discrimination', 'outlook on life/growth', 'access to public services', 'living environment', and 'control over life'. All dimensions were positively correlated to self-reported health and wellbeing, but the magnitudes in associations varied considerably (e.g., 'pain' had the strongest correlation with overall health but a weak correlation with wellbeing).

CONCLUSIONS

This study contributes to a broader understanding of QoL by exploring the dimensionality and relationships among various QoL measures. A number of the dimensions identified are HRQoL-focused, with others covering broader constructs. Our findings offer insights for the development of comprehensive instruments, or use of instrument suites that capture multidimensional aspects of QoL. Further research should explore the relevance and feasibility/appropriateness of measuring the identified dimensions in different settings and populations.

Measurement invariance and adapted preferences: evidence for the ICECAP-A and WeRFree instruments

BACKGROUND

Self-report instruments are used to evaluate the effect of interventions. However, individuals adapt to adversity. This could result in individuals reporting higher levels of well-being than one would expect. It is possible to test for the influence of adapted preferences on instrument responses using measurement invariance testing. This study conducts such a test with the Wellbeing Related option-Freedom (WeRFree) and ICECAP-A instruments.

METHODS

A multi-group confirmatory factor analysis was conducted to iteratively test four increasingly stringent types of measurement invariance: (1) configural invariance, (2) metric invariance, (3) scalar invariance, and (4) residual invariance. Data from the Multi Instrument Comparison study were divided into subsamples that reflect groups of participants that differ by age, gender, education, or health condition. Measurement invariance was assessed with (changes in) the Comparative Fit Index (CFI), Root Mean Square Error of Approximation (RMSEA), and Root Mean Square Residual (SRMR) fit indices.

RESULTS

For the WeRFree instrument, full measurement invariance could be established in the gender and education subsamples. Scalar invariance, but not residual invariance, was established in the health condition and age group subsamples. For the ICECAP-A, full measurement invariance could be established in the gender, education, and age group subsamples. Scalar invariance could be established in the health group subsample.

CONCLUSIONS

This study tests the measurement invariance properties of the WeRFree and ICECAP-A instruments. The results indicate that these instruments were scalar invariant in all subsamples, which means that group means can be compared across different subpopulations. We suggest that measurement invariance of capability instruments should routinely be tested with a reference group that does not experience a disadvantage to study whether responses could be affected by adapted preferences.

The Feasibility and Validity of Preference-Based Quality of Life Measures With Informal Carers: A Think-Aloud Study

OBJECTIVES

A range of preference-based quality of life (QoL) measures have been proposed for use with informal carers. Qualitative evaluation of validity and feasibility of the measures is an important step in understanding whether measures will work as intended. At present, little is known about the performance of different types of preference-based QoL measures with informal carers. The objective of this study was to qualitatively assess the feasibility, content validity (including face validity), and acceptability of 5 QoL measures (the Carer Experience Scale, CarerQoL-7D, ASCOT-C, ICECAP-A, and EQ-5D-5L) with informal carers.

METHODS

A total of 24 "think-aloud" interviews were conducted with a cross-section of carers of adults in the United Kingdom. This think-aloud process was followed by semistructured discussion to probe issues of validity and feasibility in more detail. The interview data were transcribed, coded to identify the frequency of errors in completing the QoL measures and thematically analyzed to study the validity, feasibility, and acceptability of the measures.

RESULTS

Few errors (3%-7% per item) were identified in completing each of the measures with little distinct pattern. Most participants found the measures to be concise, clear, and relevant. Challenges included relevance, context, time period, missing items, multiple questions, and response options. Informal carers generally expressed a preference for using a care-related QoL measure.

CONCLUSIONS

Existing preference-based QoL measures have encouraging validity and feasibility within a mixed sample of informal carers, with minor challenges raised. These challenges ought to be considered, alongside the decision context, when administering QoL measures in this context.

Estimating loss in capability wellbeing in the first year of the COVID-19 pandemic: a cross-sectional study of the general adult population in the UK, Australia and the Netherlands

OBJECTIVES

To estimate capability wellbeing lost from the general adult populations in the UK, Australia and the Netherlands in the first year of the COVID-19 pandemic and the associated social restrictions, including lockdowns.

DESIGN

Cross-sectional with recalled timepoints.

SETTING

Online panels in the UK, Australia and the Netherlands conducted in February 2021 (data collected 26 January-2 March 2021).

PARTICIPANTS

Representative general adult (≥ 18 years old) population samples in the UK (n = 1,017), Australia (n = 1,011) and the Netherlands (n = 1,017) MAIN OUTCOME MEASURE: Participants completed the ICECAP-A capability wellbeing measure in February 2021, and for two recalled timepoints during the initial lockdowns in April 2020 and in February 2020 (prior to COVID-19 restrictions in all three countries). ICECAP-A scores on a 0-1 no capability-full capability scale were calculated for each timepoint. Societal willingness to pay estimates for a year of full capability (YFC) was used to place a monetary value associated with change in capability per person and per country. Paired t tests were used to compare changes in ICECAP-A and YFC from pre- to post-COVID-19-related restrictions in each country.

RESULTS

Mean (standard deviation) loss of capability wellbeing during the initial lockdown was 0.100 (0.17) in the UK, 0.074 (0.17) in Australia and 0.049 (0.12) in the Netherlands. In February 2021, losses compared to pre-lockdown were 0.043 (0.14) in the UK, 0.022 (0.13) in Australia and 0.006 (0.11) in the Netherlands. In monetary terms, these losses were equivalent to £14.8 billion, AUD$8.6 billion and €2.1 billion lost per month in April 2020 and £6.4 billion, A$2.6 billion and €260 million per month in February 2021 for the UK, Australia and the Netherlands, respectively.

CONCLUSIONS

There were substantial losses in capability wellbeing in the first year of the COVID-19 pandemic. Future research is required to understand the specific impact of particular COVID-19 restrictions on people's capabilities.

Unmet Parenthood Goals, Health-Related Quality of Life and Apparent Irrationality: Understanding the Value of Treatments for Infertility

An increasing number of prospective parents are experiencing infertility along with associated negative impacts on mental health and life satisfaction that can extend across a network of individuals and family members. Assistive reproductive technologies (ART) can help prospective parents achieve their parenthood goals but, like any health technology, they must demonstrate acceptable 'value for money' to qualify for public funding. We argue that current approaches to understanding the value of ART, including quality-adjusted life-year (QALY) gains based on changes in health-related quality of life (HRQOL) and, more often, cost per live birth, are too narrow to capture the full impact of unmet parenthood goals and ART. We see a fundamental disconnect between measures of HRQOL and broader measures of wellbeing associated with met and unmet parenthood goals. We also suggest that simple concepts such as 'patient' and 'carer' are of limited applicability in the context of ART, where 'spillovers' extend across a wide network of individuals, and the person receiving treatment is often not the infertile individual. Consideration of individual and societal wellbeing beyond HRQOL is necessary to understand the full range of negative impacts associated with unmet parenthood goals and the corresponding positive impacts of successful ART. We suggest moving towards a wellbeing perspective on value to achieve a fuller understanding of value and promote cross-sector allocative efficiency.

Cost-effectiveness of three internet-based interventions for eating disorders: A randomized controlled trial

OBJECTIVE

The primary aim was assessing the cost-effectiveness of an internet-based self-help program, expert-patient support, and the combination of both compared to a care-as-usual condition.

METHOD

An economic evaluation from a societal perspective was conducted alongside a randomized controlled trial. Participants aged 16 or older with at least mild eating disorder symptoms were randomly assigned to four conditions: (1) Featback, an online unguided self-help program, (2) chat or e-mail support from a recovered expert patient, (3) Featback with expert-patient support, and (4) care-as-usual. After a baseline assessment and intervention period of 8 weeks, five online assessments were conducted over 12 months of follow-up. The main result constituted cost-utility acceptability curves with quality-of-life adjusted life years (QALYs) and societal costs over the entire study duration.

RESULTS

No significant differences between the conditions were found regarding QALYs, health care costs and societal costs. Nonsignificant differences in QALYs were in favor of the Featback conditions and the lowest societal costs per participant were observed in the Featback only condition (€16,741) while the highest costs were seen in the care-as-usual condition (€28,479). The Featback only condition had the highest probability of being efficient compared to the alternatives for all acceptable willingness-to-pay values.

DISCUSSION

Featback, an internet-based unguided self-help intervention, was likely to be efficient compared to Featback with guidance from an expert patient, guidance alone and a care-as-usual condition. Results suggest that scalable interventions such as Featback may reduce health care costs and help individuals with eating disorders that are currently not reached by other forms of treatment.

PUBLIC SIGNIFICANCE STATEMENT

Internet-based interventions for eating disorders might reach individuals in society who currently do not receive appropriate treatment at low costs. Featback, an online automated self-help program for eating disorders, was found to improve quality of life slightly while reducing costs for society, compared to a do-nothing approach. Consequently, implementing internet-based interventions such as Featback likely benefits both individuals suffering from an eating disorder and society as a whole.

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.

Comparison of capability and health-related quality of life instruments in capturing aspects of mental well-being in people with schizophrenia and depression

BACKGROUND

There is increasing evidence that assessing outcomes in terms of capability provides information beyond that of health-related quality of life (HRQoL) for outcome evaluation in mental health research and clinical practice.

AIMS

To assess similarities and differences in the measurement properties of the ICECAP-A capability measure and Oxford Capabilities Questionnaire for Mental Health (OxCAP-MH) in people with schizophrenia experiencing depression, and compare these measurement properties with those of (a) the EuroQol EQ-5D-5L and EuroQol Visual Analogue Scale (EQ-VAS) and (b) mental health-specific (disease-specific) measures.

METHOD

Using data for 100 patients from the UK, measurement properties were compared using correlation analyses, Bland-Altman plots and exploratory factor analysis. Responsiveness was assessed by defining groups who worsened, improved or remained unchanged, based on whether there was a clinically meaningful change in the instrument scores between baseline and 9-month follow-up assessments.

RESULTS

The two capability instruments had stronger convergent validity with each other (Spearman's rho = 0.677) than with the HRQoL (rho = 0.354-0.431) or the mental health-specific (rho = 0.481-0.718) instruments. The OxCAP-MH tended to have stronger correlations with mental health-specific instruments than the ICECAP-A, whereas the ICECAP-A had slightly stronger correlation with the EQ-VAS. Change scores on the capability instruments correlated weakly with change scores on the HRQoL scales (rho = 0.131-0.269), but moderately with those on mental health-specific instruments for the ICECAP-A (rho = 0.355-0.451) and moderately/strongly on the OxCAP-MH (rho = 0.437-0.557).

CONCLUSIONS

Assessing outcomes in terms of capabilities for people with schizophrenia and depression provided more relevant, mental health-specific information than the EQ-5D-5L or the EQ-VAS. The ICECAP-A and the OxCAP-MH demonstrated similar psychometric properties, but the OxCAP-MH was more correlated with disease-specific instruments.

The ICEpop Capability Measure for Adults Instrument for Capabilities: Development of a Tariff for the Dutch General Population

OBJECTIVES

The ICEpop Capability Measure for Adults (ICECAP-A) assesses 5 capabilities (stability, attachment, autonomy, achievement, and enjoyment) that are important to one's quality of life and might be an important addition to generic health questionnaires currently used in economic evaluations. This study aimed to develop a Dutch tariff of the Dutch translation of the ICECAP-A.

METHODS

The methods used are similar to those used in the development of the UK tariff. A profile case best-worst scaling task was presented to 1002 participants from the general Dutch population. A scale-adjusted latent class analysis was performed to test for preferences of ICECAP-A capabilities and scale heterogeneity.

RESULTS

A 3-preference class 2-scale class model with worst choice as scale predictor was considered optimal and was used to calculate the resulting tariff. Results indicated that the capabilities stability, attachment, and enjoyment were considered more important aspects of quality of life than autonomy and achievement. Additionally, improving capabilities from low to moderate levels had a larger effect on quality of life than improving capabilities that were already at a higher level.

CONCLUSIONS

The ICECAP-A tariffs found in this study could be used in economic evaluations of healthcare interventions in The Netherlands.

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.

Challenges in developing capability measures for children and young people for use in the economic evaluation of health and care interventions

Methods for measuring outcomes suitable for economic evaluations of health and care interventions have primarily focused on adults. The validity of such methods for children and young people is questionable in areas including the outcome domains measured and how they are measured and valued, with most existing measures narrowly focusing on health. Novel methods for assessing benefits beyond health by focusing on a person's capability have also concentrated on adults to date. This paper aims to set out the rationale for capability measures in children and young people. It argues for the need to expand the evaluative space beyond health functioning towards broader capabilities, with children and young people playing an integral role in capability measure development. Drawing from existing literature, specific challenges related to the identification, measurement, and valuation of capabilities in children and young people are also discussed. Finally, the practical implications for conducting economic evaluation when measuring and valuing capabilities at different stages across the life-course are illustrated. We develop an alternative framework based on conceiving capabilities as evolving across the life-course. This framework may also be helpful in thinking about how to model health outcomes across the life-course.

The ICECAP-A instrument for capabilities: assessment of construct validity and test-retest reliability in a general Dutch population

PURPOSE

The ICEpop CAPability measure for Adults (ICECAP-A) assesses five capabilities that are important to one's well-being. The instrument might be an important addition to generic health questionnaires when evaluating quality of life extending beyond health. This study aimed to conduct a psychometric assessment of the Dutch translation of the ICECAP-A.

METHODS

Construct validity of the instrument was assessed in two ways. First, by measuring correlations with the EQ-5D-5L questionnaire and a measure of self-efficacy and, second, by investigating the ability to distinguish between groups known to differ on the construct the ICECAP-A means to capture. Additionally, test-retest reliability was evaluated.

RESULTS

In total, 1002 participants representative of the general Dutch population completed an online survey. For test-retest reliability, 252 participants completed the same questionnaire 2 weeks later. The ICECAP-A indicated moderate to strong correlations with the EQ-5D-5L and a strong correlation with self-efficacy. Furthermore, it was capable of differentiating known groups. Moreover, results indicated adequate test-retest reliability with an intraclass correlation coefficient of 0.79.

CONCLUSION

In summary, results suggest adequate test-retest reliability and construct validity and indicate that the ICECAP-A might be of added value, especially when considering areas outside of the traditional health intervention model.

Measurement properties of the ICECAP-A capability well-being instrument among dermatological patients

BACKGROUND

Capability well-being captures well-being based on people's ability to do the things they value in life. So far, no capability well-being measures have been validated in dermatological patients.

OBJECTIVES

To validate the adult version of the ICEpop CAPability measure (ICECAP-A) in patients with dermatological conditions. We aimed to test floor and ceiling effects, structural, convergent and known-group validity, and measurement invariance.

METHODS

In 2020, an online, cross-sectional survey was carried out in Hungary. Respondents with self-reported physician-diagnosed dermatological conditions completed the ICECAP-A, Satisfaction with Life Scale (SWLS), WHO-5 Well-Being Index and two dermatology-specific measures, Dermatology Life Quality Index (DLQI) and Skindex-16.

RESULTS

618 respondents (mean age 51 years) self-reported a physician-diagnosed dermatological condition, with warts, eczema, onychomycosis, acne and psoriasis being the most common. ICECAP-A performed well with no floor and mild ceiling effects. The violation of local independence assumption was found between the attributes of 'attachment' and 'enjoyment'. ICECAP-A index scores correlated strongly with SWLS and WHO-5 (r_s = 0.597-0.644) and weakly with DLQI and Skindex-16 (r_s = - 0.233 to - 0.292). ICECAP-A was able to distinguish between subsets of patients defined by education and income level, marital, employment and health status. Multigroup confirmatory factor analysis indicated measurement invariance across most of these subgroups.

CONCLUSIONS

This is the first study to validate a capability well-being measure in patients with dermatological conditions. The ICECAP-A was found to be a valid tool to assess capability well-being in dermatological patients. Future work is recommended to test measurement properties of ICECAP-A in chronic inflammatory skin conditions.

Eliciting a monetary threshold for a year of sufficient capability to inform resource allocation decisions in public health and social care

AIM

To elicit a deliberative monetary value for a year of sufficient capability well-being (YSC) and a year of full capability (YFC), to inform decision-making in the contexts of social care and public health.

METHODS

69 members of the public, recruited from purposively selected electoral wards across the West Midlands Region of England, attended one of six deliberative workshops in 2017. Participants were informed about the nature of public health and social care, and the funding of these services by local authorities. Participants were then asked to report: their willingness to pay additional tax (ring-fenced for social care/public health services); and the maximum amount they would be willing to allocate for social care/public health services from an existing local authority budget. In both cases they were asked to assume that the funding would result in improved well-being equivalent to a YSC. The second task was repeated for improved well-being equivalent to a YFC. Representatives from the six initial workshops reconvened at a consensus workshop to arrive at a final arbitrated value for a YSC and YFC.

RESULTS

Mean values elicited during the initial workshops increased after discussion (from £442 to £451 in the case of WTP additional tax). Almost half of participants changed their response post-discussion when reporting a societal (aggregated) WTP. The arbitrated value of a YSC was £33,500, with a range of £33,500 to £36,150 emerging as the value of a YFC.

DISCUSSION

This is the first study to use a deliberative approach to elicit a monetary threshold for an additional YSC/YFC. Qualitative research supports the validity of responses to the taxation question. Deliberation appears to have influenced the societal (aggregated) values reported by participants.

CONCLUSION

Future research should explore the robustness of a monetary threshold of £33,500 for a YSC.

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.

Empirical Validity of a Generic, Preference-Based Capability Wellbeing Instrument (ICECAP-A) in the Context of Spinal Cord Injury

BACKGROUND

Assessing the validity of generic instruments across different clinical contexts is an important area of methodological research in economic evaluation and outcomes measurement.

OBJECTIVE

Our objective was to examine the empirical validity of a generic, preference-based capability wellbeing instrument (ICECAP-A) in the context of spinal cord injury.

METHODS

This study consisted of a secondary analysis of data collected using an online cross-sectional survey. The survey included questions regarding demographics, injury classifications and characteristics, secondary health conditions, quality of life and wellbeing, and functioning in activities of daily living. Analysis comprised the descriptive assessment of Spearman's rank correlations between item-/dimension-level data for the ICECAP-A and four preference-based health-related quality of life (HRQoL) instruments, and discriminant and convergent validity approaches to examine 21 evidence-informed or theoretically derived constructs. Constructs were defined using participant and injury characteristics and responses to a range of health, wellbeing and functioning outcomes.

RESULTS

Three hundred sixty-four individuals completed the survey. Mean index score for the ICECAP-A was 0.761; 12 (3%) individuals reported full capability (upper anchor; score = 1), and there were no reports of zero capabilities (lower anchor; score = 0). The strongest correlations were dominated by items and dimensions on the comparator (HRQoL) instruments that are non-health aspects of quality of life, such as happiness and control over one's life (including self-care). Of 21 hypothesised constructs, 19 were confirmed in statistical tests, the exceptions being the exploratory hypotheses regarding education and age at injury.

CONCLUSION

The ICECAP-A is an empirically valid outcome measure for assessing capability wellbeing in people with spinal cord injury living in a community setting. The extent to which the ICECAP-A provides complementary information to preference-based HRQoL instruments is dependent on the comparator.

Proxy responses to ICECAP-A: Exploring variation across multiple proxy assessments of capability well-being for the same individuals

Background

The ICECAP capability measures are increasingly being used to capture the impact of health and social care interventions on well-being. In cases where the recipient of an intervention is highly vulnerable, proxy completion may be necessary. This study adds to the limited existing evidence on proxy completion of ICECAP-A specifically and adopts the novel approach of investigating multiple proxy responses for the same four (hypothetical) individuals.

Methods

62 members of the public who were participating in a series of one day deliberative workshops on public health and social care completed ICECAP-A on behalf of four hypothetical individuals, described in vignettes. Quantitative analysis explored the range of proxy responses for each of the four hypothetical individuals, and any possible correlation between participants’ own characteristics and their proxy responses. Participants discussed their proxy responses after completing the task; this discussion was audio recorded and analysed using Framework Analysis.

Results

Wide variation in ICECAP-A scores was observed across proxy respondents for each hypothetical individual. Participants’ demographic characteristics and own well-being do not appear to have systematically influenced proxy responses. Qualitative analysis suggests two principal approaches (or perspectives) were adopted by participants: Empathetic (adopting the perspective of the ‘subject’) and factual (a factual assessment of the subject’s well-being). Participants also drew on their own experiences to varying degrees. There were differing interpretations of the Independence attribute on ICECAP-A and some evidence that participants’ ideas of what constituted achievement were context (including life-stage and condition/health) specific.

Conclusions

The factual versus empathetic approaches identified from qualitative analysis in this study match to the concept of a proxy-proxy versus proxy-patient perspective, previously outlined in the literature. Researchers should consider specifying which perspective proxy raters should adopt. Findings also suggest proxy responses can be influenced by external points of reference and interpretation of measure attributes.