Utility Elicitation Research Articles

PIN75 Health-Related Quality of Life of Clostridium Difficile Infection: A Methodological Contribution to Direct Utility Elicitation by TTO

PIN75 Health-Related Quality of Life of Clostridium Difficile Infection: A Methodological Contribution to Direct Utility Elicitation by TTO

Elicitation of health state utilities in soft tissue sarcoma

Soft tissue sarcomas (STS) are uncommon tumours with varying histological subtypes. There is a paucity of available data concerning the quality-of-life (QoL) impact of STS which could be used to support economic evaluation of future treatments. This study aimed to elicit societal utility values for health states that depict the impact of STS and its treatment. Following the development of eight health state vignettes, a sample of 100 members of the UK general public participated in a valuation exercise to elicit utility values using the time trade-off procedure. The treatment response state was valued as the least burdensome by participants followed by the prospect of stable disease (mean utility value: 0.736 SD 0.21). Serious adverse events were associated with a range of disutilities from -0.236 for grade III/IV pain to -0.357 for grade III/IV nausea/vomiting. Progressive disease was deemed the least desirable outcome and was associated with a substantial decline in utility (-0.473). Findings suggest advanced STS are associated with significant burden for individuals. Treatment-related adverse events were seen as debilitating, however, progression represents an enormous challenge to QoL. This illustrates the significant value to individuals of extending the progression free survival period.

METHODS—One-Switch Conditions for Multiattribute Utility Functions

We introduce a variety of new independence conditions for multiattribute utility functions that permit preference dependencies among the attributes of a decision problem. The hierarchy of new conditions varies in the degree to which it specifies the functional form, ranging from more general solutions with weaker constraints, to more specific solutions with stronger constraints. This formulation provides a wealth of new functional forms that a decision maker may use in a multiattribute decision problem. In addition, it may be used to tailor the utility elicitation process to the comfort level of the decision maker. The new conditions, and the corresponding functional forms, are based on the idea of limiting the number of switches that a decision maker may make between two decision alternatives as a parameter of the problem varies. We show how this formulation also relates many widely used concepts in single and multiattribute utility theory.

Utility elicitation study in the UK general public for late-stage chronic lymphocytic leukaemia

In the United Kingdom (UK), chronic lymphocytic leukaemia (CLL) makes up 40 % of all leukaemias in patients over 65 years. The study objective was to obtain societal preferences in the UK for "progression-free" and "progressive" states of late-stage CLL, refractory to current first and second line regimens. Preferences were also obtained for selected treatment-related adverse events (AEs). A utility elicitation study, using the time trade-off (TTO) method, was conducted by face-to-face interviews with 110 subjects for a baseline disease state (before treatment), three primary disease states [progression-free survival (PFS) and treatment responder, PFS and treatment non-responder and disease progression], and 4 AE sub-states (PFS responder with thrombocytopenia, neutropenia, and infection, and PFS non-responder with infection). TTO scores were converted into utility values, and disutilities were calculated for AEs. Visual analogue scale (VAS) scores were obtained. The primary disease state mean TTO utility scores were: baseline: 0.549; PFS response: 0.671; PFS non-response: 0.394; and progression: 0.214. The mean TTO utility (disutility) scores for the AEs were: PFS response with thrombocytopenia, 0.563 (-0.108), neutropenia, 0.508 (-0.163), and infection, 0.476 (-0.195); PFS non-response with infection, 0.333 (-0.061). The VAS results were in line with the TTO results. The utility was higher for the PFS state than baseline, but decreased below baseline in non-response and disease progression states. AEs had an impact on utility within the PFS response state. The severe infection AE had a greater impact on utilities for the responding to treatment state compared to the non-responder state.

Elicitation of health state utilities associated with differing durations of morning stiffness in rheumatoid arthritis

Objective:Specific symptoms of rheumatoid arthritis (RA), including joint stiffness and functional disability, are most severe in the morning. ‘Morning stiffness’ has a negative impact on health-related quality-of-life (HRQoL); however, how HRQoL is correlated to morning stiffness duration is unknown. The objective of this study was to obtain population-based utility values associated with different durations of morning stiffness in RA.Design and methods:The time-trade-off (TTO) approach was used to elicit utility values for four different health states (HS), which differed in morning stiffness duration. One hundred and nine members of the UK general public rated each HS in individual face-to-face interviews with trained investigators. TTO scores were converted into utility values. Visual Analog Scale (VAS) scores were obtained to validate TTO scores.Results:On a scale of 0 (death) to 1 (full health), a mean utility value of 0.45 ± 0.29 was elicited for ∼3 h of morning stiffness (anchor HS), 0.50 ± 0.28 for 2–3 h of morning stiffness (HS1), 0.61 ± 0.25 for 1–2 h of morning stiffness (HS2) and 0.78 ± 0.20 for <1 h of morning stiffness (HS3). The difference between each HS was statistically significant (p < 0.01). Mean VAS utility scores followed the same trend. Utility incrementally increased with each HS associated with a shorter duration of morning stiffness. Limitations of this research include potential bias from the TTO method due to the discounting effect of time, scale compatibility, and loss aversion.Conclusions:The UK population-based utility values show a reduction in morning stiffness duration in RA is associated with improved HRQoL. Despite the impact of morning stiffness on HRQoL, it is rarely evaluated and little is known as to how it is affected by current treatments. The results of this study can be applied in future cost-utility analyses of healthcare interventions which target an improvement in morning stiffness duration for RA patients.

Elicitation of health state utilities in neuroendocrine tumours

Background:Neuroendocrine tumours (NETs) are a rare form of neoplasm that can arise in most organs of the body and which share many common pathologic features. Although curative surgery can be conducted for patients with localised disease, once progression occurs and the disease becomes metastatic or un-resectable, treatment aims to extend life and maintain quality-of-life for as long as possible. The aim of the study was to elicit utilities for health state vignettes describing the burdens associated with receiving therapy for advanced NETs.Methods:Health state vignettes were developed by reviewing published literature and conducting in-depth interviews with patients and clinical experts. These states described the burden associated with both stable and progressive disease, in addition to the experience of a number of serious toxicities commonly associated with treatments (grade III/IV diarrhoea, hand-foot syndrome, hyperglycaemia, nausea/vomiting, pneumonitis, rash, stomatitis, and thrombocytopenia). One hundred members of the UK general public valued the states using the time trade-off methodology to determine utility values.Results:Stable disease had a utility value of 0.77 whilst disease progression was associated with a significant decline in health-related quality-of-life (HRQoL) and a value of 0.61. Toxicities experienced in the context of stable disease exhibited varying degrees of impact, with several being deemed as debilitating as disease progression (such as hand-foot syndrome [0.58] and stomatitis [0.56]).Conclusion:Although vignette studies have been criticised for the difficulty in establishing their validity, the collection of health utilities in rare populations is challenging. The findings from this study suggest that advanced NETs is associated with a considerable HRQoL burden, both as a direct result of the disease and the potential of experiencing a number of severe adverse events. These values could assist in future economic evaluation processes.

Measuring preference-based quality of life in children aged 6–7 years: a comparison of the performance of the CHU-9D and EQ-5D-Y—the WAVES Pilot Study

To examine the performance of the child health utility 9D (CHU-9D) and EuroQol 5D-youth (EQ-5D-Y) in children aged 6–7 years. The CHU-9D and EQ-5D-Y were interviewer-administered to 160 children aged 6–7 years at six schools across the West Midlands. Missing values, time taken to complete instruments and interviewer ratings were recorded to assess feasibility/acceptability. Construct validity was assessed by testing convergent validity hypotheses. Reliability was examined via a test–retest of a sub-sample. Psychometric properties were further examined by exploring distributions of utility scores, qualitative notes and design of the questionnaires. No missing responses were recorded with over 80% of children’s understanding being rated as good/excellent for both questionnaires. The average completion time for both instruments was less than 3 minutes, demonstrating excellent feasibility/acceptability. Evidence of construct validity was recorded with 12 of the 13 convergent hypotheses being supported. Test–retest reliability was relatively poor for both instruments with weighted kappa coefficients ranging from fair to moderate. Children aged 6–7 years can feasibly complete utility instruments when interviewer-administered. The reliability of the instruments is of concern and requires further study. With respect to content validity and other psychometric properties, the CHU-9D is favoured to the EQ-5D-Y. Until the EuroQol group produces tariff values for the EQ-5D-Y, we recommend that the EQ-5D-Y is not used for utility elicitation in this age group.

Health Utility Elicitation

Health Utility Elicitation

Adolescent and parental utilities for the health states associated with pelvic inflammatory disease

PurposeThere is limited information about how the consumers of adolescent pelvic inflammatory disease (PID) care value health states associated with the disorder. The aim of this study is to determine...

Recommendation Sets and Choice Queries: There Is No Exploration/Exploitation Tradeoff!

Utility elicitation is an important component of many applications, such as decision support systems and recommender systems. Such systems query users about their preferences and offer recommendations based on the system's belief about the user's utility function. We analyze the connection between the problem of generating optimal recommendation sets and the problem of generating optimal choice queries, considering both Bayesian and regret-based elicitation. Our results show that, somewhat surprisingly, under very general circumstances, the optimal recommendation set coincides with the optimal query.

Ordering Errors, Objections and Invariance in Utility Survey Responses

Utilities are the quantification of the perceived quality of life associated with any health state. They are used to calculate QALYs, the outcome measure in cost-utility analysis. Generally measured through surveys of individuals, utilities often contain apparent or unapparent errors that can bias resulting values and QALYs calculated from these values. The aim of this study was to improve direct health utility elicitation methodology through the identification of the types of survey responses that indicate errors and objections, and the reasons underlying them. We conducted a systematic review of the medical (PubMed), economics (EconLit) and psychology (PsycINFO) literature from 1975 through June 2010 for articles describing the types and frequency of errors and objections in directly elicited utility survey responses, and strategies to address these responses. Primary data were collected through an internet-based utility survey (standard gamble) of community members to identify responses that indicate error or objections. A qualitative telephone survey was conducted among a subset of respondents with these types of responses using an open-ended protocol to elicit rationales for them. A total of 11 papers specifically devoted to errors, objections and invariance in utility responses have been published since the mid-1990s. Error/objection responses can be broadly categorized into ordering errors (which include illogical and inconsistent responses) and objections/invariance (which include missing data, protest responses and refusals to trade time or risk in utility questions). Reported frequencies of respondents making ordering errors ranged from 5% to 100%, and up to 35% of respondents have been reported as objecting to the survey or task in some manner. Changes in the design, administration and analysis of surveys can address these potentially problematic responses. Survey data (n = 398) showed that individuals who provided invariant responses (n = 26) reported the lowest level of difficulty with the survey and often identified as religious (23% of invariant responders found the survey difficult vs 63% of all responders, and 77% of invariant responders identified as religious compared with 56% of entire sample; p < 0.05 for both). Respondents who provided illogical responses (n = 50) were less likely to be college educated (56% of illogical responders vs 73% of entire sample; p < 0.05), and less likely to be confident in their responses (62% vs 75% of entire sample; p < 0.05). Qualitative interviews (n = 42) following the survey revealed that the majority of ordering errors were a result of confusion, lack of attention or difficulty in responding to the survey on the part of the respondent, while invariant responses were often considered and thoughtful reactions to the premise of valuing health using the standard gamble task. Rationales for error/objection responses include difficulty in articulating preferences or misunderstanding with a complex survey task, and also thoughtful and considered protestations to the task. Mechanisms to correct unintentional errors may be useful, but cannot address intentional responses to elements of the measurement task. Identification and analysis of the prevalence of errors and objections in responses in utility data sets are essential to understanding the accuracy and precision of utility estimates and analyses that depend thereon.

The impact of CAP policy in farmer's behavior – A modeling approach using the Cumulative Prospect Theory

This paper proposes a modeling approach to evaluate the impact of economic policies on the decision maker's behavior. This modeling approach incorporates the agent's preferences, estimated through utility elicitation methods, into the objective function of a discrete sequential stochastic programming model that describes the uncertainties and the constraints faced by the decision maker. Our approach was applied to nine farmers of Portugal. The elicitation of the farmers’ preferences reveals that the Cumulative Prospect Theory is relevant to describe the farmers’ behavior under risk. Our programming model was used to evaluate the impact of the Common Agricultural Policy with partial and full decoupling of subsidies.

Utility values in National Institute for Health and Clinical Excellence (NICE) Technology Appraisals

Objective To review the selection and use of health-related utility values for economic models included in National Institute for Health and Clinical Excellence (NICE) Technology Appraisals. Method A cross-sectional review of reports of economic models submitted to the Technology Appraisals program was undertaken to review the health-related utility data included. Data reviewed included identification and selection of data and the methods used for utility elicitation. The methods used were compared with those from the 2004 Methods Guide issued by NICE. Results Appraisals conducted after the implementation of the NICE 2004 Methods Guide were reviewed. After exclusion of documents that did not include a de novo cost-utility analysis, 71 submissions (53 manufacturer submissions, 18 assessment group reports) from 39 appraisals were identified, containing 284 unique utility values. Variation was found in the selection, elicitation, valuation, and use of the utility values. Thirty-nine submissions (55%) took utility values from published studies, of which only 31% were identified through a systematic review. Forty-seven (66%) submissions contained health state descriptions reported by patients, and 55 (77%) submissions applied a valuation set derived from the general population. The EQ-5D was used in 35 (49%) submissions, and mapping to a generic health-related quality of life measure was performed in 19 (27%) submissions. Conclusions Only 56% of submissions to NICE and assessment reports included utility values that met the NICE 2004 reference case. This highlights variation in the methods used to select and incorporate utility values in economic models for NICE Technology Appraisals.

Simultaneous Elicitation of Preference Features and Utility

Most frameworks for utility elicitation assume a predefined set of features over which user preferences are expressed. We consider utility elicitation in the presence of subjective or user-defined features, whose definitions are not known in advance. We treat the problem of learning a user's feature definition as one of concept learning, but whose goal is to learn only enough about the concept definition to enable a good decision to be made. This is complicated by the fact that user utility is unknown. We describe computational procedures for identifying optimal alternatives w.r.t minimax regret in the presence of both utility and concept uncertainty; and develop several heuristic query strategies that focus simultaneously on reduction of relevant concept and utility uncertainty.

Elicitation of health state utilities in metastatic renal cell carcinoma

Objective:The aim of the study was to obtain United Kingdom societal preferences for receiving newly developed treatments for metastatic renal cell carcinoma.Methods:Health states were developed based on a literature review and in-depth interviews with clinical experts. These states described the burden of both stable and progressive disease, and a variety of commonly encountered toxicities associated with first-line therapies (fatigue, diarrhoea, nausea/vomiting, mucositis, hand/foot syndrome, hypertension and anaemia). These states were further reviewed by additional clinicians and patients to ensure their validity. One hundred members of the general public rated the states using the time trade-off (TTO) methodology to determine health state utility.Results:Stable disease had a utility value of 0.795 whilst progressive disease demonstrated a significant decline with a value of 0.355. The range of toxicities showed a variable impact in line with their toxicity grading from fatigue grade I/II (0.751) to hand/foot syndrome grade III (0.469).Conclusions:This study highlights the burden associated with a number of common toxicities encountered with current first-line mRCC treatments. Practical constraints coupled with the societal nature of the valuation exercise limited the amount of direct involvement by patients. However, these utility values should better permit the consideration of toxicity profiles in establishing the cost-effectiveness of future treatments.

The influence of probabilities on the response mode bias in utility elicitation

The response mode bias, in which subjects exhibit different risk attitudes when assessing certainty equivalents versus indifference probabilities, is a well-known phenomenon in the assessment of utility functions. In this empirical study, we develop and apply a cardinal measure of risk attitudes to analyze not only the existence, but also the strength of this phenomenon. Since probability levels involved in decision problems are already known to have a strong impact on behavior, we use this approach to study the impact of probabilities on the extent of the response mode bias. We find that the direction in which probabilities influence measured risk aversion is the opposite in the certainty equivalence (CE) method versus in the probability equivalence (PE) method. Utilizing the CE elicitation approach leads to an increase of risk seeking for gambles involving high probabilities. For the PE method, subjects tend to behave risk averse with gambles of high probabilities. This behavior is reversed in the gain domain. This “tailwhip” effect is consistently replicated in several experiments, involving both loss and gain domains of lotteries.

The utility of reliability and survival

Reliability (survival analysis, to biostatisticians) is a key ingredient for making decisions that mitigate the risk of failure. The other key ingredient is utility. A decision theoretic framework harnesses the two, but to invoke this framework we must distinguish between chance and probability. We describe a functional form for the utility of chance that incorporates all dispositions to risk, and propose a probability of choice model for eliciting this utility. To implement the model, a subject is asked to make a series of binary choices between gambles and certainty. These choices endow a statistical character to the problem of utility elicitation. The workings of our approach are illustrated via a live example involving a military planner. The material is general because it is germane to any situation involving the valuation of chance.

Elicitation of Factored Utilities

The effective tailoring of decisions to the needs and desires of specific users requires automated mechanisms for preference assessment. We provide a brief overview of recent direct preference elicitation methods: these methods ask users to answer (ideally, a small number of) queries regarding their preferences and use this information to recommend a feasible decision that would be (approximately) optimal given those preferences. We argue for the importance of assessing numerical utilities rather than qualitative preferences and survey several utility elicitation techniques from artificial intelligence, operations research, and conjoint analysis.

Impact of schizophrenia and schizophrenia treatment-related adverse events on quality of life: direct utility elicitation

ObjectiveTo examine the impact of schizophrenia, its treatment and treatment-related adverse events related to antipsychotics, on quality of life from the perspective of schizophrenia patients and laypersons.MethodsHealth state descriptions for stable schizophrenia, extra pyramidal symptoms (EPS), hyperprolactinemia, diabetes, weight gain and relapse were developed based on a review of the literature and expert opinion. The quality of life impact of each health state was elicited using a time trade-off instrument administered by interview to 49 stable schizophrenia patients and 75 laypersons. Regression techniques were employed to examine the importance of subject characteristics on health-related utility scores.ResultsPatients and laypersons completed the interview in similar times. Stable schizophrenia had the highest mean utility (0.87 and 0.92 for laypersons and patients respectively), while relapse (0.48 and 0.60) had the lowest mean utility. Of the treatment-related adverse events, EPS had the lowest mean utility (0.57 and 0.72, respectively). Age, gender and PANSS score did not influence the utility results independently of health state. On average, patient utilities are 0.077 points higher than utilities derived from laypersons, although the ranking was similar between the two groups.ConclusionEvents associated with schizophrenia and treatment of schizophrenia can bring about a significant detriment in patient quality of life, with relapse having the largest negative impact. Results indicate that patients with stable schizophrenia are less willing to trade years of life to avoid schizophrenia-related symptoms compared to laypersons. Both sets of respondents showed equal ability to complete the questionnaire.

The correction of TTO-scores for utility curvature using a risk-free utility elicitation method

This paper describes and employs a new method to correct time tradeoff (TTO)-scores for utility of life duration curvature. In contrast to most previous attempts to do so, it uses a risk-free method that corresponds well to the risk-free properties of the TTO-method. In addition, the method is robust to several biases that occur under methods that incorporate risk. Our results show a significant degree of curvature in utility of life duration and therefore a clear bias in TTO-scores. The risk-free method seems to be useful to correct TTO-scores for this influence and leads to significantly higher quality-adjustment factors.