Hospice patients' participation in choice experiments to value supportive care outcomes.

BACKGROUND: Values used in economic evaluation are typically obtained from the general public, which is problematic when measures are to be used with people experiencing a life-course stage such as the end of life. OBJECTIVE: To assess the feasibility of obtaining values for the ICECAP-Supportive Care Measure (SCM) from patients receiving advanced supportive care through a hospice. METHODS: Participants completed eight best-worst scaling questions in a think-aloud interview to explain choices in different hypothetical end-of-life scenarios. Three independent raters identified errors in completion of the best-worst scaling task, and thematic analysis of associated qualitative data was undertaken to explore task difficulty and choices. RESULTS: Twelve hospice patients were recruited. Most were able to complete the task and prioritise aspects of supportive care with either no difficulty (n=50%) or difficulty in just one of the eight scenarios (n=25%). Two patients (n=17%) were unable to comprehend the hypothetical nature of the task. The qualitative data confirmed there was good engagement with the task and identified the importance the respondents attached to maintaining dignity. CONCLUSION: The findings suggest that people at the end of life will be able to complete a short, interviewer-administered, best-worst scaling task. To maximise engagement, it is recommended that the task is short and initiated with an example. Scenarios are best presented on show-cards in large print. A full evaluation of the ICECAP-SCM with those at the end of life is feasible.

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.

Valuing the Child Health Utility 9D: Using profile case best worst scaling methods to develop a new adolescent specific scoring algorithm.

In contrast to the recent proliferation of studies incorporating ordinal methods to generate health state values from adults, to date relatively few studies have utilised ordinal methods to generate health state values from adolescents. This paper reports upon a study to apply profile case best worst scaling methods to derive a new adolescent specific scoring algorithm for the Child Health Utility 9D (CHU9D), a generic preference based instrument that has been specifically designed for the estimation of quality adjusted life years for the economic evaluation of health care treatment and preventive programs targeted at young people. A survey was developed for administration in an on-line format in which consenting community based Australian adolescents aged 11-17 years (N = 1982) indicated the best and worst features of a series of 10 health states derived from the CHU9D descriptive system. The data were analyzed using latent class conditional logit models to estimate values (part worth utilities) for each level of the nine attributes relating to the CHU9D. A marginal utility matrix was then estimated to generate an adolescent-specific scoring algorithm on the full health = 1 and dead = 0 scale required for the calculation of QALYs. It was evident that different decision processes were being used in the best and worst choices. Whilst respondents appeared readily able to choose 'best' attribute levels for the CHU9D health states, a large amount of random variability and indeed different decision rules were evident for the choice of 'worst' attribute levels, to the extent that the best and worst data should not be pooled from the statistical perspective. The optimal adolescent-specific scoring algorithm was therefore derived using data obtained from the best choices only. The study provides important insights into the use of profile case best worst scaling methods to generate health state values with adolescent populations.

Are Efficient Designs Used in Discrete Choice Experiments Too Difficult for Some Respondents? A Case Study Eliciting Preferences for End-of-Life Care.

BACKGROUND: Although efficient designs have sample size advantages for discrete choice experiments (DCEs), it has been hypothesised that they may result in biased estimates owing to some respondents using simplistic heuristics. OBJECTIVES: The main objective was to provide a case study documenting that many respondents choose on the basis of a single attribute when exposed to highly efficient DCE designs but switch to a conventional multi-attribute decision rule when the design efficiency was lowered (resulting in less need to trade across all attributes). Additional objectives included comparisons of the sizes of the estimated coefficients and characterisation of heterogeneity, thus providing evidence of the magnitude of bias likely present in highly efficient designs. METHODS: Five hundred and twenty-five respondents participating in a wider end-of-life survey each answered two DCEs that varied in their design efficiency. The first was a Street and Burgess 100% efficient Orthogonal Main Effects Plan design (2(7) in 8), using the top and bottom levels of all attributes. The second DCE comprised one eighth of the full Orthogonal Main Effects Plan in 32 pairs, (a 2 × 4(6)). Linear probability models estimated every respondent's complete utility function in DCE1. The number of respondents answering on the basis of one attribute level was noted, as was the proportion of these who then violated this rule in DCE2, the less efficient DCE. Latent class analyses were used to identify heterogeneity. RESULTS: Sixty per cent of respondents answered all eight tasks comprising DCE1 using a single attribute; most used the rule "choose cheapest end-of-life care plan". However, when answering the four less efficient tasks in DCE2, one third of these (20% overall) then traded across attributes at least once. Among those whose decision rule could not be described qualitatively, latent class models identified two classes; compared to class one, class two was more concerned with quality rather than cost of care and wished to die in an institution rather than at home. Higher efficiency was also associated with smaller regression coefficients, suggesting either weaker preferences or lower choice consistency (larger errors). CONCLUSION: This is the first within-subject study to investigate the association between DCE design efficiency and utility estimates. It found that a majority of people did not trade across attributes in the more efficient design but that one third of these then did trade in the less efficient design. More within-subject studies are required to establish how common this is. It may be that future DCEs should attempt to maximise some joint function of statistical and cognitive efficiency to maximise overall efficiency and minimise bias.

Complex Valuation: Applying Ideas from the Complex Intervention Framework to Valuation of a New Measure for End-of-Life Care.

BACKGROUND: The UK Medical Research Council approach to evaluating complex interventions moves through development, feasibility, piloting, evaluation and implementation in an iterative manner. This approach might be useful as a conceptual process underlying complex valuation tasks. OBJECTIVE: The objective of the study was to explore the applicability of such a framework using a single case study (valuing the ICECAP-Supportive Care Measure) and considering three key uncertainties: the number of response categories for the measure; experimental design; and the potential for using slightly different variants of the measure with the same value set. METHODS: Three on-line pilot studies (n = 204, n = 100, n = 102) were undertaken during 2012 and 2013 with adults from the UK general population. Each used variants of discrete choice and best-worst scaling tasks; respondents were randomly allocated to different groups to allow exploration of the number of levels for the instrument (four or five), optimal experimental design and the values for alternative wording around prognosis. Conditional logit regression models were used in the analysis and variance scale factors were explored. RESULTS: The five-level version of the measure seemed to result in simplifying heuristics. Plotting the variance scale factors suggested that best-worst scaling answers were approximately four times more consistent than the discrete choice answers. The likelihood ratio test indicated there was virtually no difference in values between the differently worded versions. CONCLUSION: Rigorous piloting can improve the design of valuation studies. Thinking in terms of a 'complex valuation framework' may emphasise the importance of conducting and funding such rigorous pilots.

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.

Outcome Preferences in Patients With Noninfectious Uveitis: Results of a Best-Worst Scaling Study.

PURPOSE: To estimate patient preferences regarding potential adverse outcomes of local versus systemic corticosteroid therapies for noninfectious uveitis by using a best-worst scaling (BWS) approach. METHODS: Local and systemic therapies are alternatives for noninfectious uveitis that have different potential adverse outcomes. Patients participating in the Multicenter Uveitis Steroid Treatment Trial Follow-up Study (MUST FS) and additional patients with a history of noninfectious uveitis treated at two academic medical centers (Johns Hopkins University and University of Pennsylvania) were surveyed about their preferences regarding six adverse outcomes deemed important to patients. Using "case 1" BWS, patients were asked to repeatedly select the most and least worrying from a list of outcomes (in the survey three outcomes per task). RESULTS: Eighty-two patients in the MUST FS and 100 patients treated at the academic medical centers completed the survey. According to BWS, patients were more likely to select vision not meeting the requirement for driving (individual BWS score: median = 3, interquartile range, 0-5), development of glaucoma (2, 1-4), and needing eye surgery (1, 0-3) as the most worrying outcomes as compared to needing medicine for high blood pressure/cholesterol (-2, -4 to 0), development of cataracts (-2, -3 to -1), or infection (sinusitis) (-3, -5 to 0). Larger BWS scores indicated the outcomes were more worrying to patients. CONCLUSIONS: Patients with noninfectious uveitis considered impaired vision, development of glaucoma, and need for eye surgery worrying adverse outcomes, which suggests that it is especially desirable to avoid these outcomes if possible. (ClinicalTrials.gov number, NCT00132691.)

Preferences for end-of-life care among community-dwelling older adults and patients with advanced cancer: A discrete choice experiment.

Singapore is in the midst of several healthcare reforms in efforts to finance and deliver health services for a rapidly aging population. The primary focus of these reforms is to make healthcare services, including those at the end of life (EOL), affordable. Given the increasingly high health care costs at the EOL, policy makers need to consider how best to allocate resources. One strategy is to allocate resources based on the preferences of sub-populations most likely to be affected. This paper thus aims to quantify preferences for EOL care both among community dwelling older adults (CDOAs) and among patients with a life-limiting illness. A discrete choice experiment was administered to CDOAs and advanced cancer patients in Singapore and willingness to pay (WTP) for specific EOL improvements was estimated. We find that patients have a higher WTP for nearly all EOL attributes compared with CDOAs. We also show that, for both groups, moderate life extension is not the most important consideration; WTP for one additional life year is lower than common thresholds for cost-effectiveness. Irrespective of whose preference are considered, the results highlight the importance of pain management and supporting home deaths at the EOL, perhaps at the expense of public funding for costly but only marginally effective treatments.

Valuing Child Health Utility 9D Health States with Young Adults: Insights from a Time Trade Off Study.

OBJECTIVES: In contrast to the proliferation of studies incorporating health state values from adults of all ages, relatively few studies have reported upon the application of the time trade off (TTO) approach to generate health state values from populations of younger adults. This study sought to employ a conventional TTO approach to obtain values for a selection of Child Health Utility 9D (CHU9D) health states from a sample of young adults aged 18-29 years and to compare with the values generated from application of the original UK adult standard gamble scoring algorithm and the Australian adolescent scoring algorithm. METHODS: A convenience sample of Flinders University undergraduate students aged 18-29 years were invited to participate in an interviewer administered conventional TTO task to value a series of five CHU9D health impairment states using the widely used variant developed by the York EQ-5D team. RESULTS: A total of 152 students within the target age range were approached to participate in the study of whom n = 38 consented to participate, giving an overall participation rate of 25%. With the exception of one health state, the mean TTO values were consistently lower than those generated from application of the original scoring algorithm for the CHU9D elicited with adults of all ages. A significant proportion of participants (n = 17, 45%) considered the most severe CHU9D (PITS) state to be worse than death. CONCLUSIONS: This study adds to a growing body of evidence indicating that the values attached to identical health states are typically lower for younger people in comparison with adults of all ages and dependent upon the elicitation method utilised. The values obtained are applicable for re-scaling raw CHU9D health state values obtained from younger adolescent samples using profile case best-worst scaling.

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.

Test-retest reliability of capability measurement in the UK general population.

Although philosophically attractive, it may be difficult, in practice, to measure individuals' capabilities (what they are able to do in their lives) as opposed to their functionings (what they actually do). To examine whether capability information could be reliably self-reported, we administered a measure of self-reported capability (the Investigating Choice Experiments Capability Measure for Adults, ICECAP-A) on two occasions, 2 weeks apart, alongside a self-reported health measure (the EuroQol Five Dimensional Questionnaire with 3 levels, EQ-5D-3L). We found that respondents were able to report capabilities with a moderate level of consistency, although somewhat less reliably than their health status. The more socially orientated nature of some of the capability questions may account for the difference.

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.

Risk as an attribute in discrete choice experiments: a systematic review of the literature.

BACKGROUND: Discrete choice experiments (DCEs) are used to elicit preferences of current and future patients and healthcare professionals about how they value different aspects of healthcare. Risk is an integral part of most healthcare decisions. Despite the use of risk attributes in DCEs consistently being highlighted as an area for further research, current methods of incorporating risk attributes in DCEs have not been reviewed explicitly. OBJECTIVES: This study aimed to systematically identify published healthcare DCEs that incorporated a risk attribute, summarise and appraise methods used to present and analyse risk attributes, and recommend best practice regarding including, analysing and transparently reporting the methodology supporting risk attributes in future DCEs. DATA SOURCES: The Web of Science, MEDLINE, EMBASE, PsycINFO and Econlit databases were searched on 18 April 2013 for DCEs that included a risk attribute published since 1995, and on 23 April 2013 to identify studies assessing risk communication in the general (non-DCE) health literature. STUDY ELIGIBILITY CRITERIA: Healthcare-related DCEs with a risk attribute mentioned or suggested in the title/abstract were obtained and retained in the final review if a risk attribute meeting our definition was included. STUDY APPRAISAL AND SYNTHESIS METHODS: Extracted data were tabulated and critically appraised to summarise the quality of reporting, and the format, presentation and interpretation of the risk attribute were summarised. RESULTS: This review identified 117 healthcare DCEs that incorporated at least one risk attribute. Whilst there was some evidence of good practice incorporated into the presentation of risk attributes, little evidence was found that developing methods and recommendations from other disciplines about effective methods and validation of risk communication were systematically applied to DCEs. In general, the reviewed DCE studies did not thoroughly report the methodology supporting the explanation of risk in training materials, the impact of framing risk, or exploring the validity of risk communication. LIMITATIONS: The primary limitation of this review was that the methods underlying presentation, format and analysis of risk attributes could only be appraised to the extent that they were reported. CONCLUSIONS: Improvements in reporting and transparency of risk presentation from conception to the analysis of DCEs are needed. To define best practice, further research is needed to test how the process of communicating risk affects the way in which people value risk attributes in DCEs.

Integrating cognitive process and descriptive models of attitudes and preferences.

Discrete choice experiments--selecting the best and/or worst from a set of options--are increasingly used to provide more efficient and valid measurement of attitudes or preferences than conventional methods such as Likert scales. Discrete choice data have traditionally been analyzed with random utility models that have good measurement properties but provide limited insight into cognitive processes. We extend a well-established cognitive model, which has successfully explained both choices and response times for simple decision tasks, to complex, multi-attribute discrete choice data. The fits, and parameters, of the extended model for two sets of choice data (involving patient preferences for dermatology appointments, and consumer attitudes toward mobile phones) agree with those of standard choice models. The extended model also accounts for choice and response time data in a perceptual judgment task designed in a manner analogous to best-worst discrete choice experiments. We conclude that several research fields might benefit from discrete choice experiments, and that the particular accumulator-based models of decision making used in response time research can also provide process-level instantiations for random utility models.

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

OBJECTIVES: This study aimed to determine quantitatively the attributes of such screening tests that couples placed most value on. METHODS: A stated preference discrete choice experiment was conducted among a sample of pregnant women and their male partners. One four-level attribute (cost) and three two-level attributes (detection rate, gestation and time to wait for results) were used to generate eight hypothetical pairs of tests. RESULTS: A total of 103 participants fully completed the questionnaire (63 women, 40 men). Overall, the sample was most concerned with test cost. However, latent class analysis showed three groups of participants whose concern for attributes differed, with cost, detection rate and delay in receiving results being the most important to each. Willingness to pay calculations showed that participants who were most concerned with detection rate were prepared to pay more than four times the amount than those most cost-sensitive would pay for the 'best test' option as compared with the 'worst test'. CONCLUSIONS: Overall, couples were sensitive to the price of the screening test, but explicit subgroups are also shown that would pay large amounts for improvements in other attributes, particularly detection rates. This could provide important information to policymakers and practitioners in antenatal care, specifically in relation to the trade-offs made when couples decide about antenatal screening tests.

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

PURPOSE: To investigate the construct validity of the ICECAP-A capability wellbeing measure. METHODS: A 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. RESULTS: The 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. CONCLUSION: This 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.

Using best-worst scaling in horizon scanning for hepatocellular carcinoma technologies.

OBJECTIVES: There is a growing need for efficient procedures for identification of emerging technologies by horizon scanning systems. We demonstrate the value of best-worst scaling (BWS) in exploring clinicians' views on emerging technologies that will impact outcomes in hepatocellular carcinoma (HCC) in the next 5 to 10 years. METHODS: Clinicians in Asia, Europe, and the United States were surveyed and their views about eleven emerging technologies relevant to HCC were explored using BWS (case 1). This involved systematically presenting respondents with subsets of five technologies and asking them to identify those that will have the most and least impact on HCC within 5 to 10 years. Statistical analysis was based on sequential best-worst and analyzed using conditional logistic regression. RESULTS: A total of 120 clinicians uniformly distributed across ten countries completed the survey (37 percent response rate). Respondents were predominately hepatologist (41 percent) who focused on HCC (65 percent) and had national influence in this field (39 percent). Respondents viewed molecular targeted therapy (p < .001) and early detection of HCC (p < .001) as having most potential, while improved surgical techniques (p < .001) and biopsy free HCC diagnostics (p < .001) were viewed upon negatively. CONCLUSIONS: We demonstrate that BWS could be an important research tool to facilitate horizon scanning and HTA more broadly. Our research demonstrates the value of including clinicians' preferences as a source of data in horizon scanning, but such methods could be used to incorporate the opinions of a broad array of stakeholders, including those in advocacy and public policy.

Whose values in health? An empirical comparison of the application of adolescent and adult values for the CHU-9D and AQOL-6D in the Australian adolescent general population.

OBJECTIVES: The Child Health Utility-9D (CHU-9D) and the Assessment of Quality of Life-6D (AQOL-6D) presently represent the only two generic preference-based instruments developed for application with young people with both adult- and adolescent-specific scoring algorithms. The main objective of this study was to compare and contrast the application of adult and adolescent scoring algorithms for the CHU-9D and AQOL-6D in valuing the health of a community-based sample of adolescents. METHODS: A Web-based survey including the CHU-9D and the AQOL-6D was developed for administration to adolescents, aged 11 to 17 years, residing in Australia (n = 500). Individual responses to both instruments were converted to values by using first the adult and second the adolescent scoring algorithms pertaining to each instrument. RESULTS: Both the AQOL-6D and the CHU-9D discriminated well according to health status and the presence of long-standing illness regardless of the scoring algorithm. Within each instrument, however, important discrepancies were found in that employment of the adolescent algorithm was found to result in consistently lower mean health state values for the CHU-9D but consistently higher mean health state values for the AQOL-6D relative to the employment of their respective adult algorithms and these differences were statistically significant (P < 0.05). CONCLUSION: The differences in adolescent and adult values for identical health states are more profound for the CHU-9D and ultimately may be significant enough to have an impact on health care policy. It is important to note that there are important differences between the CHU-9D instrument and the AQOL-6D instrument that may also have a significant impact on the valuations obtained.