Elisabeth Huynh

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.

Assessing the Health-Related Quality of Life of Australian Adolescents: An Empirical Comparison of the Child Health Utility 9D and EQ-5D-Y Instruments.

OBJECTIVES To examine the performance of two recently developed preference-based instruments-the Child Health Utility 9D (CHU9D) and the EuroQol five-dimensional questionnaire Youth version (EQ-5D-Y)-in assessing the health-related quality of life (HRQOL) of Australian adolescents. METHODS An online survey including the CHU9D and the EQ-5D-Y, self-reported health status, and a series of sociodemographic questions was developed for administration to a community-based sample of adolescents (aged 11-17 years). Individual responses to both instruments were translated into utilities using scoring algorithms derived from the Australian adult general population. RESULTS A total of 2020 adolescents completed the online survey. The mean ± SD utilities of the CHU9D and the EQ-5D-Y were very similar (0.82 ± 0.13 and 0.83 ± 0.19, respectively), and the intraclass correlation coefficient (0.80) suggested good levels of agreement. Both instruments were able to discriminate according to varying levels of self-reported health status (P < 0.001). Although exhibiting good levels of agreement overall, some wide divergences were apparent at an individual level. CONCLUSIONS The study results are encouraging and illustrate the potential for both the CHU9D and the EQ-5D-Y to be more widely used for measuring and valuing the HRQOL of adolescent populations in Australia and internationally. Generating adolescent-specific scoring algorithms pertaining to each instrument and an empirical comparison of the resulting utilities is a natural next step. More evidence is required from the application of the CHU9D and the EQ-5D-Y in specific patient groups in adolescent health settings to inform the choice of instrument for measuring and valuing the HRQOL for the economic evaluation of adolescent health care treatments and services.

NOTHING ABOUT US WITHOUT US? A COMPARISON OF ADOLESCENT AND ADULT HEALTH‐STATE VALUES FOR THE CHILD HEALTH UTILITY‐9D USING PROFILE CASE BEST–WORST SCALING

The main objective of this study was to compare and contrast adolescent and adult values for the Child Health Utility-9D (CHU9D), a new generic preference-based measure of health-related quality of life designed for application in the economic evaluation of treatment and preventive programmes for children and adolescents. Previous studies have indicated that there may be systematic differences in adolescent and adult values for identical health states. An online survey including a series of best-worst scaling discrete choice experiment questions for health states defined by the CHU9D was administered to two general population samples comprising adults and adolescents, respectively. The results highlight potentially important age-related differences in the values attached to CHU9D dimensions. Adults, in general, placed less weight upon impairments in mental health (worried, sad, annoyed) and more weight upon moderate to severe levels of pain relative to adolescents. The source of values (adults or adolescents) has important implications for economic evaluation and may impact significantly upon healthcare policy.

Values for the ICECAP-Supportive Care Measure (ICECAP-SCM) for use in economic evaluation at end of life

End of life care may have elements of value that go beyond health. A generic measure of the benefits of end of life care could be helpful to decision makers. Such a measure, based on the capability approach, has recently been developed: the ICECAP Supportive Care Measure. This paper reports the first valuation exercise for that measure, with data from 6020 individuals collected from an on-line general population panel during June 2013. Individuals were asked to complete a stated choice experiment that combined best-worst scaling and a standard discrete choice experiment. Analysis of the best-worst data used limited dependent variable models within the random utility framework including the multinomial logit models and latent class choice model analysis. Exploratory steps were taken to determine the similarity of the best-worst and DCE data before formal testing and pooling of the two data sources. Combined data were analysed in a heteroscedastic conditional logit model adjusting for continuous scale. Two sets of tariffs were generated, one from the best-worst data capturing only main effects, and a second from the pooled data allowing for two-way interactions. Either tariff could be used in economic evaluation of interventions at the end of life, although there are advantages and disadvantages with each. This extensive valuation exercise for the ICECAP Supportive Care Measure, with a large number of members of the general public, could be complemented in the future with best-worst scaling studies amongst those experiencing the end of life.

Protocol for a systematic review of instruments for the assessment of quality of life and well-being in children and adolescents with cerebral palsy

Introduction Cerebral palsy is the most common cause of physical disability in children and adolescents and is associated with impairments that may reduce the quality of life (QOL) of this population. Patient-reported outcome measures (PROMs) can facilitate the assessment of the effect of disease and treatment on QOL, from a patient viewpoint. The purpose of this systematic review is to identify PROMs that are used to measure QOL and subjective well-being (SWB) outcomes in young people with cerebral palsy and to evaluate the suitability of these PROMs for application in economic evaluations within this population. Methods and analysis MEDLINE, Scopus, the Cochrane Library, Web of Science Core Collection, EconLit, PsycINFO, CINAHL, EMBASE and Informit will be systematically searched from inception to date of search. Published peer-reviewed, English-language articles reporting PROMs measuring QOL or SWB outcomes in children and adolescents with cerebral palsy will be included. One reviewer will conduct the initial search and screen titles and abstracts for potentially eligible studies. The search will be performed in November 2017. To reduce the likelihood of reviewer selection bias, two other reviewers will independently screen a randomly selected subsample (10%) of the citations. Two reviewers will then retrieve full texts of potentially eligible studies and assess them against predefined inclusion criteria. The suitability of selected PROMs for use in economic evaluations of young people with cerebral palsy will be assessed using the International Society of Quality of Life Research recommended Minimum Standards and the Patient-Centered Outcomes and Comparative Effectiveness Research checklist. A narrative synthesis of extracted data will be presented including study descriptive data, PROMs measurement properties, settings in which they were applied and the valuation methods. Recommendations for practice on the selection of PROMs for use in economic evaluations of children and adolescents with cerebral palsy will be presented. Ethics and dissemination Ethical approval is not required as the proposed systematic review will not use primary data. The results of this study will be widely disseminated through publication in a peer-reviewed journal and conference presentation(s). Systematic review registration number International Prospective Register of Systematic Reviews number: CRD42016049746.

A review of preference-based measures for the assessment of quality of life in children and adolescents with cerebral palsy

PurposeTo examine the psychometric properties and suitability for use within the context of cerebral palsy research in children and adolescents of generic preference-based outcome measures (PROMs).MethodsNine electronic databases were searched in this systematic review. The consensus-based standards for the selection of health measurement instruments (COSMIN) checklist were used to measure the psychometric properties of the PROMs. A meta-analysis was used to pool correlation coefficients for convergent validity using the Schmidt–Hunter method. Heterogeneity was assessed using the I-squared statistic (I2).ResultsFour preference-based PROMs were identified from eight studies: Health Utilities Index—Mark 2 and 3 (HUI-2 and HUI-3, respectively), the Assessment Quality of Life-4 dimension (AQoL-4D) and the EuroQol-5 dimension 3 level (EQ-5D-3L). Only the HUI system was primarily developed for application with children/adolescents though health-state values for scoring the PROM were elicited from adults. The HUI-3 covered the most relevant constructs though it excludes important modules of health-related quality of life (HRQOL) such as activity limitations and participation restrictions. In terms of psychometric properties, evidence was presented for only five of COSMIN measurement properties: reliability (HUI3), measurement error (HUI-3), content validity (HUI-2 and HUI-3), Hypotheses testing (HUI-3 and AQoL-4D) and criterion validity (HUI-3). No papers reported on internal consistency, structural validity, cross-cultural validity or responsiveness of the preference-based measures in children and adolescents with cerebral palsy.ConclusionsThis review highlights the dearth in studies using preference-based PROMs to measure HRQOL associated with cerebral palsy in children and adolescents. The HUI-3 demonstrated the strongest psychometric properties, though it does not cover all dimensions relevant to this population.

Preference Elicitation at the End of Life

Conventional economic evaluation methods are likely unsuitable for valuing end-of-life care. This chapter describes much simpler tasks called discrete choice experiments as an alternative. It uses an Australian study and summarises work on the research frontier which offers the prospect of validating the stated preferences of individuals using physiological (response time) data. Such data also appear to be able to distinguish Kahneman’s “fast” (emotional) and “slow” (considered) decision-making styles, which will provide clinicians and policymakers with much more information about what is driving an individual’s views.

BWS object case application: attitudes towards end-of-life care

7.1 Introduction This chapter uses Case 1 – the object case – to elicit the views of older Australians towards different, and potentially competing, end-of-life care strategies. In addition to the empirical aims of the original article, this chapter aims to illustrate to those working in health how Case 1 BWS techniques used previously in personality assessment can be used to elicit attitudes towards health care.The proportion of the Australian population aged 65 and over grew from 8.5 percent in 1961 to 13.3 percent in 2009. This proportion is predicted to rise to 21.3 percent in 2031, which has implications for health and social care service provision, particularly if there are continuing reductions in the proportion of an Australians life that is spent contributing to the system in tax. This aging issue is common to most of the developed world. Costly, and burdensome, interventions to preserve life are increasingly used. While advances in medical care mean that such highly interventionist strategies return some patients to a health state approximating that experienced before the deterioration, in many cases these treatments serve only to prolong the dying process or return the patient to a highly impaired state in which activities of daily living cannot be performed. Many individuals do not want this expensive and potentially intrusive care (SUPPORT investigators, 1995). Doctors and family members generally choose interventionist treatment for patients who cannot make their own choice, unless patients make their wishes clear in advance. However, the process of thought leading to the creation of an advance care plan is difficult for most patients (Baker et al ., 2013), and only a minority complete plans at present, so clinicians often have little information about an individual patients treatment preferences. Advance care planning (ACP) is typically conducted in an interview that is necessarily long and complex, because of the need to consider various medical interventions that might be applied singly, or in combination, in different circumstances. Outcomes can vary, in terms of chance of survival, treatment burden and quality of life. Therefore, traditional ACP interviews have typically been qualitative in nature (Singer, Martin and Kelner, 1999), making them impossible to scale up to the population level. However, ACP has to be scaled up to this level, not least because end-of-life care is both emotive and resource-intensive to society.