Environmental impact assessment in health technology assessment: principles, approaches, and challenges.

To reduce harm to the environment resulting from the production, use, and disposal of health technologies, there are different options for how health technology assessment (HTA) agencies can consider environmental information. We identified four approaches that HTA agencies can use to take environmental information into account in healthcare decision making and the challenges associated with each approach. Republishing data that is in the public domain or has been submitted to an HTA agency we term the "information conduit" approach. Analyzing and presenting environmental data separately from established health economic analyses is described as "parallel evaluation." Integrating environmental impact into HTAs by identifying or creating new methods that allow clinical, financial, and environmental information to be combined in a single quantitative analysis is "integrated evaluation." Finally, evidence synthesis and analysis of health technologies that are not expected to improve health-related outcomes but claim to have relative environmental benefits are termed "environment-focused evaluation."

Exploration of the Reasons Why Health State Valuation Differs for Children Compared With Adults: A Mixed Methods Approach.

OBJECTIVES: Evidence comparing utilities for adults and children consistently report higher utility values for child health states. This study investigates the reasons why child health states are valued differently. METHODS: A total of 80 respondents (United Kingdom, Belgium, The Netherlands) participated in 1.5-hour face-to-face interviews. Respondents valued 4 health states from 2 perspectives (8-year-old child, 40-year-old adult) using visual analog scale and time trade-off. A total of 32 respondents participated in think-aloud interviews. Audio recordings were analyzed by 2 independent coders using NVIVO software. Statements, nodes, and themes were reviewed cyclically until consensus was reached. RESULTS: Qualitative results: a total of 5 themes were identified in the data regarding child and adult valuation-intergenerational responsibility and dependency (childhood is crucial for forming life skills based on new experiences; adulthood is an important time to take care of the family), staying alive is important (life is worth living even with impaired health-related quality of life (HRQoL), for children and adults), awareness of poor HRQoL and ability to make decisions (children have difficulties comprehending poor HRQoL and their parents make their healthcare decision; adults can assess their own HRQoL and decide for themselves), coping ability (children are flexible and resilient; adults have experience with dealing with difficulties), and practical organization of care (children are cared for by their parents; adults are able to organize and pay for care). Mixed methods: comparing qualitative statements with respondents' higher utilities for child health states confirmed concordance between results. CONCLUSIONS: Quality-adjusted life-years are interpreted differently for children and adults. Child-specific value sets are needed to reflect society's preferences and to adequately conduct health technology assessment of pediatric treatments.

Does Changing the Age of a Child to be Considered in 3-Level Version of EQ-5D-Y Discrete Choice Experiment-Based Valuation Studies Affect Health Preferences?

OBJECTIVES: There has been some debate about the choice of perspective and the age of the child considered when completing preference elicitation tasks in the 3-level version of EQ-5D-Y (EQ-5D-Y-3L) valuation protocol. This study aimed to clarify the impact on latent scale EQ-5D-Y-3L values of varying the age of the child experiencing the health state considered by respondents completing the discrete choice experiment (DCE) tasks of the protocol. METHODS: We conducted an online DCE with a representative sample of 1000 adults in the United Kingdom and 1000 adults in the United States. Respondents selected the health state they prefer from a series of DCE paired EQ-5D-Y-3L health state comparisons using their own perspective and that of a hypothetical child from the following age groups: "5-7 years old," "8-10 years old," "11-13 years old," and "14-15 years old." Data analysis was conducted using separate multinomial logit models for each perspective and country. We also estimated combined models including data from each possible pair of perspectives and used interactions between EQ-5D-Y-3L levels and perspective to determine whether any differences were statistically significant. RESULTS: No statistically significant differences in coefficients between perspectives were found in the United States. In the United Kingdom, there were differences between the own perspective and the 5 to 7 years old perspective (looking after myself level 3) and between the 5 to 7 years old perspective and the 8 to 10 years old perspective (usual activities level 3). CONCLUSIONS: Our results suggest that there is minimal impact on latent scale values when using different ages of the hypothetical child in the current EQ-5D-Y-3L valuation protocol.

Criteria for developing, assessing and selecting candidate EQ-5D bolt-ons.

PURPOSE: 'Bolt-on' dimensions are additional items added to multi-attribute utility instruments (MAUIs) such as EQ-5D that measure constructs not included in the core descriptive system. The use of bolt-ons has been proposed to improve the content validity and responsiveness of the descriptive system in certain settings and health conditions. EQ-5D bolt-ons serve a particular purpose and thus satisfy a certain set of criteria. The aim of this paper is to propose a set of criteria to guide the development, assessment and selection of candidate bolt-on descriptors. METHODS: Criteria were developed using an iterative approach. First, existing criteria were identified from the literature including those used to guide the development of MAUIs, the COSMIN checklist and reviews of existing bolt-ons. Second, processes used to develop bolt-ons based on qualitative and quantitative approaches were considered. The information from these two stages was formalised into draft development and selection criteria. These were reviewed by the project team and iteratively refined. RESULTS: Overall, 23 criteria for the development, assessment and selection of candidate bolt-ons were formulated. Development criteria focused on issues relating to i) structure, ii) language, and iii) consistency with the existing EQ-5D dimension structure. Assessment and selection criteria focused on face and content validity and classical psychometric indicators. CONCLUSION: The criteria generated can be used to guide the development of bolt-ons across different health areas. They can also be used to assess existing bolt-ons, and inform their inclusion in studies and patient groups where the EQ-5D may lack content validity.

Spotlight environmental sustainability: a strategic priority for NICE.

This article provides the context for the ambition outlined in the the National Institute for Health and Care Excellence (NICE) 2021-2026 strategy to 'lead globally on the potential to include environmental impact data in its guidance to reduce the carbon footprint of health and care'. Anthropogenic environmental changes pose a catastrophic risk to human health, with potential to widen national and global health inequalities. Recognising the fact that NICE guidance influences the way health and care is delivered and its consequent environmental impact, NICE has included environmental sustainability among its strategic priorities. This article outlines the work underway to meet this sustainability agenda at NICE.

Incorporating environmental and sustainability considerations into health technology assessment and clinical and public health guidelines: a scoping review.

Healthcare systems account for a substantial proportion of global carbon emissions and contribute to wider environmental degradation. This scoping review aimed to summarize the evidence currently available on incorporation of environmental and sustainability considerations into health technology assessments (HTAs) and guidelines to support the National In stitute for Health and Care Excellence and analogous bodies in other jurisdictions developing theirown methods and processes. Overall, 7,653 articles were identified, of which 24 were included in this review and split into three key areas - HTA (10 studies), healthcare guidelines (4 studies), and food and dietary guidelines (10 studies). Methodological reviews discussed the pros and cons of different approaches to integrate environmental considerations into HTAs, including adjustments to conventional cost-utility analysis (CUA), cost-benefit analysis, and multicriteria decision analysis. The case studies illustrated the challenges of putting this into practice, such as lack of disaggregated data to evaluate the impact of single technologies and difficulty in conducting thorough life cycle assessments that consider the full environmental effects. Evidence was scant on the incorporation of environmental impacts in clinical practice and public health guidelines. Food and dietary guidelines used adapted CUA based on life cycle assessments, simulation modeling, and qualitative judgments made by expert panels. There is uncertainty on how HTA and guideline committees will handle trade-offs between health and environment, especially when balancing environmental harms that fall largely on society with health benefits for individuals. Further research is warranted to enable integration of environmental considerations into HTA and clinical and public health guidelines.

The EQ-5D-5L Value Set for England: Response to the "Quality Assurance".

OBJECTIVES: To respond to the 'quality assurance' of the EQ-5D-5L value set for England study. METHODS: We provide a point-by-point response to the issues raised by the authors of the quality assurance paper, drawing on theoretical arguments, empirical analyses and practical considerations. RESULTS: We provide evidence to show that many of the points made by the authors of the quality assurance are misleading, suggest misunderstandings, or are irrelevant. CONCLUSIONS: The modeling approaches which were used appropriately address the characteristics of the data and provide a reasonable representation of the average stated preferences of general public in England. We provide reflections on the conduct of stated preference studies, and suggestions for the way forward.

A note on the relationship between age and health-related quality of life assessment.

PURPOSE: To extend existing analyses of whether and how the age of respondents is related to their time trade-off (TTO) valuations of hypothetical EQ-5D-3L health states, and to contribute to the existing debate about the rationale and implications for using age-specific utilities in health technology assessment (HTA). METHODS: We use data from the MVH UK valuation study. For each profile, the mean TTO value-adjusted by sex, education, self-reported health and personal experience of serious illness-is pairwise compared across the different age groups. A Bonferroni correction is applied to the multiple testing of significant differences between means. Smile plots illustrate the results. A debate regarding whether there is a case for using age-specific utilities in HTAs complements the analysis. RESULTS: Results show that the oldest respondents value health profiles lower than younger age groups, particularly for profiles describing problems in the mobility dimension. CONCLUSION: The findings raise the possibility of using age-specific value sets in HTAs, since a technology may not be cost-effective on average but cost-effective for a sub-group whose preferences are more closely aligned to the benefits offered by the technology.

Evaluation of Split Version and Feedback Module on the Improvement of Time Trade-Off Data.

BACKGROUND: EQ-5D-5L valuation studies previously reported many inconsistent responses in time trade-off (TTO) data. A number of possible elements, including ordering effects of the valuation tasks, mistakes at the sorting question, and interviewers' (learning) effects, may contribute to their inconsistency. OBJECTIVES: This study aimed to evaluate the effect of two modifications on consistency of TTO data in The Netherlands (NL) and Hong Kong (HK): (1) separating the valuation of the Better than Dead (BTD) and Worse than Dead (WTD) states; and (2) Implementation of feedback (FB) module by offering an opportunity to review TTO responses. METHODS: A crossover design with two study arms was used to test the effect of the modifications. In each jurisdiction, six interviewers were involved where half the interviewers started using the standard version, and the other half started with the split version. Each version was switched after every 25 (NL) or 30 (HK) interviews until 400 interviews were completed. RESULTS: In the NL and HK, 404 and 403 respondents participated, respectively. With the use of the FB module, the proportion of respondents with inconsistent responses was lowered from 17.8% to 10.6% (P < 0.001) in NL and from 31.8% to 22.3% (P = 0.003) in HK. The result of separating the valuation of BTD and WTD states was not straightforward because it reduced the inconsistency rate in NL but not in HK. CONCLUSIONS: The results support implementation of the FB module to promote the consistency of the data. The separation of the BTD and WTD task is not supported.

Valuation of EuroQol Five-Dimensional Questionnaire, Youth Version (EQ-5D-Y) and EuroQol Five-Dimensional Questionnaire, Three-Level Version (EQ-5D-3L) Health States: The Impact of Wording and Perspective.

BACKGROUND: Valuations of health states were affected by the wording of the two instruments (EQ-5D-3L and EQ-5D-Y) and by the perspective taken (child or adult). OBJECTIVES: There is a growing demand for value sets for the EQ-5D-Y (EQ-5D instrument for younger populations). Given the similarities between EQ-5D-Y and EQ-5D-3L, we investigated whether valuations of health states were affected by the differences in wording between the two instruments and by the perspective taken in the valuation exercise (child or adult). STUDY DESIGN: Respondents were randomly assigned to EQ-5D-3L or EQ-5D-Y (instrument) and further into two groups that either valued health states for an adult or for a 10-year-old child (perspective). The valuation tasks were composite time trade-off (C-TTO) and discrete choice experiments (DCE), including comparisons with death (DCE + death). Members of the adult general population in four countries (Germany, Netherlands, Spain, England) participated in computer-assisted personal interviews. METHODS: Two-way multivariate analysis of variance (MANOVA) and post hoc tests were used to compare C-TTO responses and chi-square tests were conducted to compare DCE + death valuations. RESULTS: A significant interaction effect between instrument and perspective for C-TTO responses was found. Significant differences by perspective (adult and child) occurred only for the EQ-5D-3L. Significant differences in values between instruments (EQ-5D-3L and EQ-5D-Y) occurred only for the adult perspective. Both significant results were confirmed by the DCE + death results. When comparing EQ-5D-3L for adult perspective and EQ-5D-Y for child perspective, values were also significantly different. CONCLUSIONS: The results identified an interaction effect between wording of the instrument and perspective on elicited values, suggesting that current EQ-5D-3L value sets should not be employed to assign values to EQ-5D-Y health states.

Euthanasia, religiosity and the valuation of health states: results from an Irish EQ5D5L valuation study and their implications for anchor values.

BACKGROUND: The Quality Adjusted Life Year influences the allocation of significant amounts of healthcare resources. Despite this surprisingly little research effort has been devoted to analysing how beliefs and attitudes to hastening death influence preferences for health states anchored at "dead" and "perfect health". In this paper we examine how, inter alia, adherence to particular religious beliefs (religiosity) influences attitudes to euthanasia and how, inter alia, attitudes to euthanasia influences the willingness to assign worse than dead (WTD) values to health states using data collected as part of the Irish EQ5D5L valuation study. METHODS: A sample of 160 respondents each supplied 10 composite time trade-off valuations and information on religiosity and attitudes to euthanasia as part of a larger national survey. Data were analysed using a recursive bivariate probit model in which attitudes to euthanasia and willingness to assign WTD values were analysed jointly as functions of a range of covariates. RESULTS: Religiosity was a significant determinant of attitudes to euthanasia and attitudes to euthanasia were a significant determinant of the likelihood of assigning WTD values. A significant negative correlation in errors between the two probit models was observed indicative of support for the hypothesis of endogeneity between attitudes to euthanasia and readiness to assign WTD values. CONCLUSION: In Ireland attitudes and beliefs play an important role in understanding health state preferences. Beyond Ireland this may have implications for: the construction of representative samples; understanding the values accorded health states and; the frequency with which value sets must be updated.

New methods for modelling EQ-5D-5L value sets: An application to English data.

Value sets for the EQ-5D-5L are required to facilitate its use in estimating quality-adjusted life years. An international protocol has been developed to guide the collection of stated preference data for this purpose and has been used to generate EQ-5D-5L valuation data for England. The aim of this paper is report the innovative methods used for modelling those data to obtain a value set. Nine hundred and ninety-six members of the English general public completed time trade-off (TTO) and discrete choice experiment (DCE) tasks. We estimate models, with and without interactions, using DCE data only, TTO data only, and TTO/DCE data combined. TTO data are interpreted as both left and right censored. Heteroskedasticity and preference heterogeneity between individuals are accounted for. We use Bayesian methods in the econometric analysis. The final model is chosen based on the deviance information criterion (DIC). Censoring and taking account of heteroskedasticity have important effects on parameter estimation. For DCE data only, TTO data only, and DCE/TTO data combined, models with parameters for all dimensions and levels perform best, as judged by the DIC. Taking account of heterogeneity improves fit, and the multinomial model reports the lowest DIC. This paper presents approaches that suit observed characteristics of EQ-5D-5L valuation data and recognise respondents' preference heterogeneity. The methods described are potentially relevant to other value set studies.

Valuing health-related quality of life: An EQ-5D-5L value set for England.

A new version of the EQ-5D, the EQ-5D-5L, is available. The aim of this study is to produce a value set to support use of EQ-5D-5L data in decision-making. The study design followed an international research protocol. Randomly selected members of the English general public completed 10 time trade-off and 7 discrete choice experiment tasks in face-to-face interviews. A 20-parameter hybrid model was used to combine time trade-off and discrete choice experiment data to generate values for the 3,125 EQ-5D-5L health states. Valuation data are available for 996 respondents. Face validity of the data has been demonstrated, with more severe health states generally given lower values. Problems with pain/discomfort and anxiety/depression received the greatest weight. Compared to the existing EQ-5D-3L value set, there are considerably fewer "worse than dead" states (5.1%, compared with over one third), and the minimum value is higher. Values range from -0.285 (extreme problems on all dimensions) to 0.950 (for health states 11211 and 21111). Results have important implications for users of the EQ-5D-5L both in England and internationally. Quality-adjusted life year gains from interventions seeking to improve very poor health may be smaller using this value set and may previously have been overestimated.

An Empirical Study of Two Alternative Comparators for Use in Time Trade-Off Studies.

BACKGROUND: Studies to produce value sets for preference-based measures of health require definition of a full health upper anchor if the values are to be used to calculate quality-adjusted life years. Recent value sets derived for the EQ-5D-5L instrument have described the upper anchor as "full health," whereas older valuation studies for the EQ-5D used "best health state" in the descriptive system (11111). It is unclear whether this change could have led to differences in the values obtained. The objective of this study was to assess differences in time trade-off (TTO) valuations using two different comparators (full health and 11111). METHODS: Preferences for EQ-5D-5L health states were elicited from a broadly representative sample of the UK general public. TTO data were collected by using computer-assisted personal interviews. Respondents were randomly allocated to one of two arms, each using a different comparator health state. Respondents completed 10 or 11 TTO valuations and a series of follow-up questions examining their interpretations of the term "full health." RESULTS: Interviews with 443 respondents were completed in 2014. The differences in mean values across arms are mostly small and nonsignificant. The two arms produced data of similar quality. There is evidence of interviewer effects. Health state 11111 was given a value of 1 by 98.2% of the respondents who valued it. CONCLUSIONS: EQ-5D-5L values elicited by using the composite TTO approach are not greatly affected by the use of full health or 11111 as the comparator health state.

Valuing Health Using Time Trade-Off and Discrete Choice Experiment Methods: Does Dimension Order Impact on Health State Values?

BACKGROUND: Health states defined by multiattribute instruments such as the EuroQol five-dimensional questionnaire with five response levels (EQ-5D-5L) can be valued using time trade-off (TTO) or discrete choice experiment (DCE) methods. A key feature of the tasks is the order in which the health state dimensions are presented. Respondents may use various heuristics to complete the tasks, and therefore the order of the dimensions may impact on the importance assigned to particular states. OBJECTIVE: To assess the impact of different EQ-5D-5L dimension orders on health state values. METHODS: Preferences for EQ-5D-5L health states were elicited from a broadly representative sample of members of the UK general public. Respondents valued EQ-5D-5L health states using TTO and DCE methods across one of three dimension orderings via face-to-face computer-assisted personal interviews. Differences in mean values and the size of the health dimension coefficients across the arms were compared using difference testing and regression analyses. RESULTS: Descriptive analysis suggested some differences between the mean TTO health state values across the different dimension orderings, but these were not systematic. Regression analysis suggested that the magnitude of the dimension coefficients differs across the different dimension orderings (for both TTO and DCE), but there was no clear pattern. CONCLUSIONS: There is some evidence that the order in which the dimensions are presented impacts on the coefficients, which may impact on the health state values provided. The order of dimensions is a key consideration in the design of health state valuation studies.

IS THE LINK BETWEEN HEALTH AND WEALTH CONSIDERED IN DECISION MAKING? RESULTS FROM A QUALITATIVE STUDY.

OBJECTIVES: The aim of this study was to explore whether wealth effects of health interventions, including productivity gains and savings in other sectors, are considered in resource allocations by health technology assessment (HTA) agencies and government departments. To analyze reasons for including, or not including, wealth effects. METHODS: Semi-structured interviews with decision makers and academic experts in eight countries (Australia, France, Germany, Italy, Poland, South Korea, Sweden, and the United Kingdom). RESULTS: There is evidence suggesting that health interventions can produce economic gains for patients and national economies. However, we found that the link between health and wealth does not influence decision making in any country with the exception of Sweden. This is due to a combination of factors, including system fragmentation, methodological issues, and the economic recession forcing national governments to focus on short-term measures. CONCLUSIONS: In countries with established HTA processes and methods allowing, in principle, the inclusion of wider effects in exceptional cases or secondary analyses, it might be possible to overcome the methodological and practical barriers and see a more systematic consideration of wealth effect in decision making. This would be consistent with principles of efficient priority setting. Barriers for the consideration of wealth effects in government decision making are more fundamental, due to an enduring separation of budgets within the public sector and current financial pressures. However, governments should consider all relevant effects from public investments, including healthcare, even when benefits can only be captured in the medium- and long-term. This will ensure that resources are allocated where they bring the best returns.

PAYER PERSPECTIVES ON FUTURE ACCEPTABILITY OF COMPARATIVE EFFECTIVENESS AND RELATIVE EFFECTIVENESS RESEARCH.

OBJECTIVES: Our objective was to gather perspectives from payers on how comparative effectiveness research (CER) in the United States and relative effectiveness (RE) research in Europe will impact evidentiary standards for access decisions of new drugs by 2020. METHODS: We conducted semi-structured interviews with fourteen senior officials representing public and private payers, health technology assessment groups, and pricing and reimbursement bodies in the United States and Europe. An online survey assessed current use of CER/RE evidence and potential trends that might influence its use for decision making by 2020. A semi-structured interview elicited payers' definitions of CER/RE and was structured around four hypothetical cases resembling drugs expected to be more common or poised to create policy challenges by 2020. Topics included acceptance of study designs and analytic methods associated with CER/RE. A systematic content review was done to extract relevant information. RESULTS: According to key informants, randomization will remain an essential component for assessing comparative or relative effectiveness. They anticipate greater use of policy levers such as conditional reimbursement or prior authorization to manage diffusion of new drugs. Case studies provided important insights into situations when certain types of CER evidence may be acceptable (e.g., observational data when differences between drugs are largely convenience). CONCLUSIONS: Industry perceptions that CER/RE will change payers' evidentiary requirements in the future are consistent with our findings. Growing investment in payers' own data and increased reliance on policy tools to control diffusion of new drugs may also influence the type of evidence industry will be required to produce by 2020.

Government and charity funding of cancer research: public preferences and choices.

BACKGROUND: It is unclear how the public would respond to changes in government decisions about how much to spend on medical research in total and specifically on major disease areas such as cancer. Our aim was to elicit the views of the general public in the United Kingdom about how a change in government spending on cancer research might affect their willingness to donate, or to hypothecate a portion of their income tax payments, to cancer research charities. METHODS: A web-based stated preference survey was conducted in 2013. Respondents considered hypothetical scenarios regarding changes in the levels of government funding for medical research. In each scenario, respondents were asked to imagine that they could allocate £100 of the income tax they paid this year to one or more medical research charities. They were asked how they wished to allocate the £100 between cancer research charities and medical research charities concerned with diseases other than cancer. After having been given the opportunity to allocate £100 in this way, respondents were then asked if they would want to reduce or increase any personal out-of-pocket donations that they already make to cancer research and non-cancer medical research charities. Descriptive analyses and random effects modelling were used to examine patterns in the response data. RESULTS: The general tendency of respondents was to act to offset hypothetical changes in government spending. When asked to imagine that the government had reduced (or increased) its spending on cancer research, the general tendency of respondents was to state that they would give a larger (or smaller) allocation of their income tax to cancer research charities, and to increase (or reduce) their personal out-of-pocket donations to cancer research charities. However, most respondents' preferred allocation splits and changes in personal donations did not vary much from scenario to scenario. Many of the differences between scenarios were small and non-significant. CONCLUSIONS: The public's decisions about how much to donate to cancer research or other medical research charities are not greatly affected by (hypothetical) changes to government plans about the amount of public funding of cancer or other medical research.

Multinational evidence of the applicability and robustness of discrete choice modeling for deriving EQ-5D-5L health-state values.

AIMS: To investigate the feasibility of discrete choice experiments for valuing EQ-5D-5L states using computer-based data collection, the consistency of the estimated regression coefficients produced after modeling the preference data, and to examine the similarity of the values derived across countries. METHODS: Data were collected in Canada, England, The Netherlands, and the United States (US). Interactive software was developed to standardize the format of the choice tasks across countries, except for face-to-face interviewing in England. The choice task required respondents to choose between 2 suboptimal health states. A Bayesian design was used to generate 200 pairs of states that were randomly grouped into 20 blocks. Each respondent completed 1 block of 10 pairs. A main-effects probit model was used to estimate regression coefficients and to derive values. RESULTS: Approximately 400 respondents participated from each country. The mean time to perform 1 choice task was between 29.2 (US) and 45.2 (England) seconds. All regression coefficients were statistically significant, except level 2 for Usual Activities in The Netherlands (P=0.51). Predictions for the complete set of 3125 EQ-5D-5L health states were similar for the 4 countries. Intraclass correlation coefficients between the countries were high: from 0.80 (England vs. US) through 0.98 (Canada vs. US) CONCLUSIONS: Derivation of value sets from the general population using computer-based choice tasks for the EQ-5D-5L is feasible. Parameter estimates were generally consistent and logical, and health-state values were similar across the 4 countries.

Rationale, conceptual issues, and resultant protocol for a mixed methods Person Trade Off (PTO) and qualitative study to estimate and understand the relative value of gains in health for children and young people compared to adults.

BACKGROUND: Economic evaluation of healthcare typically assumes that an identical health gain to different patients has the same social value. There is some evidence that the public may give greater value to gains for children and young people, although this evidence is not always consistent. We present a mixed methods study protocol where we aim to explore public preferences regarding health gains to children and young people relative to adults, in an Australian setting. METHODS: This study is a Person Trade Off (PTO) choice experiment that incorporates qualitative components. Within the PTO questions, respondents will be asked to choose between treating different groups of patients that may differ in terms of patient characteristics and group size. PTO questions will be included in an online survey to explore respondent views on the relative value of health gains to different age groups in terms of extending life and improving different aspects of quality of life. The survey will also contain attitudinal questions to help understand the impact of question style upon reported preferences. Additionally, the study will test the impact of forcing respondents to express a preference between two groups compared with allowing them to report that the two groups are equivalent. One-to-one 'think aloud', semi-structured interviews will be conducted to explore a sub-sample of respondents' motivations and views in more detail. Focus groups will be conducted with members of the public to discuss the study findings and explore their views on the role of public preferences in health care prioritisation based on patient age. DISCUSSION: Our planned study will provide valuable information to healthcare decision makers in Australia who may need to decide whether to pay more for health gains for children and young people compared with adults. Additionally, the methodological test of forcing respondent choice or allowing them to express equivalence will contribute towards developing best practice methods in PTO studies. The rationale for and advantages of the study approach and potential limitations are discussed in the protocol.