Hareth Al-Janabi

Development of a self-report measure of capability wellbeing for adults: the ICECAP-A

PurposeThe benefits of health and social care are not confined to patient health alone and therefore broader measures of wellbeing may be useful for economic evaluation. This paper reports the development of a simple measure of capability wellbeing for adults (ICECAP-A).MethodsIn-depth, informant-led, interviews to identify the attributes of capability wellbeing were conducted with 36 adults in the UK. Eighteen semi-structured, repeat interviews were carried out to develop a capability-based descriptive system for the measure. Informants were purposively selected to ensure variation in socio-economic status, age, sex, ethnicity and health. Data analysis was carried out inductively and iteratively alongside interviews, and findings were used to shape the questions in later interviews.ResultsFive over-arching attributes of capability wellbeing were identified for the measure: “stability”, “attachment”, “achievement”, “autonomy” and “enjoyment”. One item, with four response categories, was developed for each attribute for the ICECAP-A descriptive system.ConclusionsThe ICECAP-A capability measure represents a departure from traditional health economics outcome measures, by treating health status as an influence over broader attributes of capability wellbeing. Further work is required to value and validate the attributes and test the sensitivity of the ICECAP-A to healthcare interventions.

Using qualitative methods for attribute development for discrete choice experiments: issues and recommendations

Attribute generation for discrete choice experiments (DCEs) is often poorly reported, and it is unclear whether this element of research is conducted rigorously. This paper explores issues associated with developing attributes for DCEs and contrasts different qualitative approaches. The paper draws on eight studies, four developed attributes for measures, and four developed attributes for more ad hoc policy questions. Issues that have become apparent through these studies include the following: the theoretical framework for random utility theory and the need for attributes that are neither too close to the latent construct nor too intrinsic to peoples personality; the need to think about attribute development as a two-stage process involving conceptual development followed by refinement of language to convey the intended meaning; and the difficulty in resolving tensions inherent in the reductiveness of condensing complex and nuanced qualitative findings into precise terms. The comparison of alternative qualitative approaches suggests that the nature of data collection will depend both on the characteristics of the question (its sensitivity, for example) and the availability of existing qualitative information. An iterative, constant comparative approach to analysis is recommended. Finally, the paper provides a series of recommendations for improving the reporting of this element of DCE studies.

Estimation of a Preference-Based Carer Experience Scale:

Background. There is growing interest in incorporating the effects of interventions on unpaid carers in economic evaluation. Current methods focus on using health measures (which neglect important aspects of care-related quality of life) or using carer-specific sum score measures (which are not preference based). Objective. To estimate preference-based index values for a profile measure of the caring experience (the Carer Experience Scale). Methods. Eighteen profiles from the Carer Experience Scale were included in a best-worst scaling experiment. In each profile, respondents were asked to pick the best and worst attribute level from the profiles. The choice task was completed in a postal questionnaire by 162 unpaid carers of older people from 5 geographical locations in the United Kingdom. Logistic regression was used to estimate utility weights for the attribute levels of the Carer Experience Scale. Alternative modeling assumptions were employed to determine the stability of the parameter estimates. These parameter estimates were rescaled so that the profile index values for the Carer Experience Scale lay on a 0-to-100 scale. Results. The results indicate that low levels of “activities” and “getting on” result in larger decrements to utility than other attributes of the caring experience. In general, greater value is placed on differences between the bottom and middle levels of attributes than between the middle and top levels. Alternative modeling approaches had a negligible effect on the index values. Conclusion. The index values reported in this study offer a new preference-based approach to incorporating the effects on carers in economic evaluation, focusing on care (rather than health)–related quality of life.

Scoring the Icecap-a Capability Instrument. Estimation of a UK General Population Tariff†

This paper reports the results of a best–worst scaling (BWS) study to value the Investigating Choice Experiments Capability Measure for Adults (ICECAP-A), a new capability measure among adults, in a UK setting. A main effects plan plus its foldover was used to estimate weights for each of the four levels of all five attributes. The BWS study was administered to 413 randomly sampled individuals, together with sociodemographic and other questions. Scale-adjusted latent class analyses identified two preference and two (variance) scale classes. Ability to characterize preference and scale heterogeneity was limited, but data quality was good, and the final model exhibited a high pseudo-r-squared. After adjusting for heterogeneity, a population tariff was estimated. This showed that ‘attachment’ and ‘stability’ each account for around 22% of the space, and ‘autonomy’, ‘achievement’ and ‘enjoyment’ account for around 18% each. Across all attributes, greater value was placed on the difference between the lowest levels of capability than between the highest. This tariff will enable ICECAP-A to be used in economic evaluation both within the field of health and across public policy generally.

An investigation of the construct validity of the ICECAP-A capability measure

PurposeTo investigate the construct validity of the ICECAP-A capability wellbeing measure.MethodsA face-to-face interview-administered survey was conducted with 418 members of the UK general population, randomly sampled from the Postcode Address File. Pre-specified hypotheses were developed about the expected associations between individuals’ ICECAP-A responses and their socio-economic circumstances, health and freedom. The hypotheses were investigated using statistical tests of association.ResultsThe ICECAP-A responses and scores reflected differences across different health and socioeconomic groups as anticipated, but did not distinguish individuals by the level of local deprivation. Mean ICECAP-A scores reflected individuals’ perceived freedom slightly more closely than did measures of health and happiness.ConclusionThis study suggests that the ICECAP-A measure can identify expected differences in capability wellbeing in a general population sample. Further work could establish whether self-reported capabilities exhibit desirable validity and acceptability in sub-groups of the population such as patients, social care recipients and informal carers.

QALYs and Carers

When going ‘beyond the patient’, to measure QALYs for unpaid carers, a number of additional methodological considerations and value judgements must be made. While there is no theoretical reason to restrict the measurement of QALYs to patients, decisions have to be made about which carers to consider, what instruments to use and how to aggregate and present QALYs for carers and patients. Current, albeit limited, practice in measuring QALY gains to carers in economic evaluation varies, suggesting that there may be inconsistency in judgements about whether interventions are deemed cost effective.While conventional health-related quality-of-life tools can, in theory, be used to estimate QALYs, there are both theoretical and empirical concerns over the suitability of their use with carers. Measures that take a broader view of health or well-being may be more appropriate. Incorporating QALYs of carers in economic evaluations may have important distributional consequences and, therefore, greater normative discussion over the appropriateness of incorporating these impacts is required. In the longer term, more flexible forms of cost-per-QALY analysis may be required to take account of the broader impacts on carers and the weight these impacts should receive in decision making.

A qualitative assessment of the content validity of the ICECAP-A and EQ-5D-5L and their appropriateness for use in health research.

Purpose The ICECAP-A and EQ-5D-5L are two index measures appropriate for use in health research. Assessment of content validity allows understanding of whether a measure captures the most relevant and important aspects of a concept. This paper reports a qualitative assessment of the content validity and appropriateness for use of the eq-5D-5L and ICECAP-A measures, using novel methodology. Methods In-depth semi-structured interviews were conducted with research professionals in the UK and Australia. Informants were purposively sampled based on their professional role. Data were analysed in an iterative, thematic and constant comparative manner. A two stage investigation - the comparative direct approach - was developed to address the methodological challenges of the content validity research and allow rigorous assessment. Results Informants viewed the ICECAP-A as an assessment of the broader determinants of quality of life, but lacking in assessment of health-related determinants. The eq-5D-5L was viewed as offering good coverage of health determinants, but as lacking in assessment of these broader determinants. Informants held some concerns about the content or wording of the Self-care, Pain/Discomfort and Anxiety/Depression items (EQ-5D-5L) and the Enjoyment, Achievement and attachment items (ICECAP-A). Conclusion Using rigorous qualitative methodology the results suggest that the ICECAP-A and EQ-5D-5L hold acceptable levels of content validity and are appropriate for use in health research. This work adds expert opinion to the emerging body of research using patients and public to validate these measures.

A framework for including family health spillovers in economic evaluation

Health care interventions may affect the health of patients’ family networks. It has been suggested that these “health spillovers” should be included in economic evaluation, but there is not a systematic method for doing this. In this article, we develop a framework for including health spillovers in economic evaluation. We focus on extra-welfarist economic evaluations where the objective is to maximize health benefits from a health care budget (the “health care perspective”). Our framework involves adapting the conventional cost-effectiveness decision rule to include 2 multiplier effects to internalize the spillover effects. These multiplier effects express the ratio of total health effects (for patients and their family networks) to patient health effects. One multiplier effect is specified for health benefit generated from providing a new intervention, one for health benefit displaced by funding this intervention. We show that using multiplier effects to internalize health spillovers could change the optimal funding decisions and generate additional health benefits to society.

Women and their partners' preferences for Down's syndrome screening tests: a discrete choice experiment

This study aimed to determine quantitatively the attributes of such screening tests that couples placed most value on.

Women and their partners' preferences for Down's syndrome screening tests

This study aimed to determine quantitatively the attributes of such screening tests that couples placed most value on.