J.A. van Til

The effect of information on preferences stated in a choice-based conjoint analysis

OBJECTIVE The objective of the study was to investigate the effect of a priori information on preferences for treatment elicited in a discrete choice experiment. METHODS A convenience sample of 100 subjects was randomly split into two groups. The groups received minimal or extensive information on the treatment of ankle and foot impairment in stroke. Then, they participated in a discrete choice experiment. Possible treatment was described using eight decision criteria with two to four levels each. Part-worth utility coefficients for the criteria levels, criteria importance and overall treatment preference were estimated. It was tested whether the amount of information that was received influenced the outcome of the discrete choice experiment. RESULTS In the extensively informed group fewer reversals in the expected order of part-worth utilities were found. Criteria importance for four of the eight criteria and criteria importance ranking between the minimally and extensively informed subject groups were significantly different. The difference in part-worth utility of the levels had a minor effect on the predicted utility of the available treatments. CONCLUSION The lower number of level rank reversals in the extensively informed subjects indicates a better understanding of outcome desirability and thus a better understanding of the decision task. The effect of more extensive information on predicted treatment preference was minimal. PRACTICE IMPLICATIONS While interpreting the results of a discrete choice experiment, the effect of prior knowledge on the decision problem has to be taken into account. Although information seems to increase the understanding of the decision task, outcomes valuation can also be directed by information and more extensive information increases the cognitive burden which is placed on the subjects. Future research should focus on the exact nature and size of the effects and the results of this study should be clinically validated.

Preferences of general practitioners regarding an application running on a personal digital assistant in acute stroke care.

An application was developed to optimize information exchange in acute stroke care, with which general practitioners (GPs) could consult hospital emergency units. However, it was difficult to obtain clear preferences from GPs regarding the functional requirements of the information to be transferred or the architecture of the application. Thirteen GPs volunteered to take part in the study. The GPs used a personal digital assistant in their daily work for a period of six weeks when visiting stroke patients during their evening, night and weekend shifts. A conjoint analysis was conducted to obtain the least and most preferred characteristics of the application, to facilitate implementation on a larger scale. The main outcome was that GPs preferred the decision-support facilities and the presence of information about the patients medical history.

PIH66 – A Systematic Review To Identify the Use of Preference Elicitation Methods in Health Care Decision Making

Objectives: Preference elicitation methods (PEMs) offer the potential to increase patient-centered medical decision-making (MDM), by offering a measure of benefit along with a measure of value. Preferences can be applied in decisions on: reimbursement, including health technology assessment (HTA); market access, including benefit-risk assessment (BRA), and clinical care. The three decision contexts have different requirements for use and elicitation of preferences. The aim of this systematic review was to identify studies that used PEMs to represent the patient view and identify the types of health care decisions addressed by PEMs. Additionally, PEMs were described by methodological and practical characteristics within the three contexts’ requirements. Methods: Search terms included those related to MDM and patient preferences. Only articles with original data from quantitative PEMs were included. Results: Articles (n=322) selected included 379 PEMs, comprising matching methods (MM) (n=71,18.7%), discrete choice experiments (DCE) (n=96,25.3%), multi-criteria decision analysis (n=12,3. 2%), and other methods (i. e. rating scales), which provide estimates inconsistent with utility theory (n=200,52.8%). Most publications of PEMs had an intended use for clinical decisions (n=134,40%), HTA (n=68,20%), or BRA (n=12,4%). However, many did not specify an intended use (n=156,41.1%). In clinical decisions, rating, ranking, visual analogue scales and direct choice are used most often. In HTA, DCEs and MM are both used frequently, and the elicitation of preferences in BRA was limited to DCEs. Conclusions: Relatively simple preference methods are often adequate in clinical decisions, because they are easy to administer, give fast results, place low cognitive burden on the patient, and low analytical burden on the provider. MM and DCE fulfill the requirements of HTA and BRA but are more complex for the respondents. There were no PEMs that had low cognitive burden, and strong methodological underpinnings which could deliver adequate information to inform HTA and BRA decisions.

WOMEN'S PREFERENCES AND WILLINGNESS-TO-PAY FOR SINGLE NUCLEOTIDE POLYMORPHISMS GENE TESTING IN A MULTI-ETHNIC ASIAN POPULATION

PHASE 2 OPEN-LABEL EXTENSION (OLE) STUDY OF PATISIRAN, AN INVESTIGATIONAL RNA INTERFERENCE (RNAI) THERAPEUTIC FOR THE TREATMENT OF HEREDITARY ATTR AMYLOIDOSIS WITH POLYNEUROPATHYOBJECTIVES Maturity onset diabetes of the young (MODY) is a genetic form of diabetes for which 13 genes are known to be responsible. Many subtypes of MODY can be treated with oral medication instead of insulin injections, which results in improved metabolic control, quality of life and cost savings. Massively parallel sequencing (MPS) enables the simultaneous sequencing of all 13 genes for a fraction of the cost of traditional Sanger sequencing. We conducted a cost utility analysis of genetic screening (targeted MPS) for MODY in a paediatric population presumed to have type 1 diabetes (T1D), where the underlying prevalence of MODY has been calculated as 2.6%. METHODS A Markov decision model was developed to estimate the incremental costs and quality-adjusted life years (QALYs) of genetic screening for MODY compared with standard care over 50 years’ follow up. The probabilities and quality of life weightings (utility) of long term diabetic complications were estimated from published data and population statistics. Costs were estimated from the perspective of the Australian health care system. RESULTS Genetic screening for MODY at diabetes diagnosis was more effective and less costly than standard care, with 1.39 QALYs gained and AU

PND60 - Comparison of the valuation of treatment alternatives in Parkinson's disease with best-wordt scaling, time trade-off and visual analogue scales

1.4 million (US

PRM139 – How Do Individuals Complete The Choice Tasks In A Discrete Choice Experiment?

1.05 million) saved per 1,000 patients. The costs of the screening program were fully offset within four years. A sensitivity analysis revealed that genetic screening remained dominant until the MODY prevalence fell below 0.7%. CONCLUSIONS Screening for MODY in the paediatric diabetes population would reduce health system costs and improve patient quality of life. Our results were robust to assumptions around the underlying MODY prevalence and make a compelling argument for routine genetic screening in all children with presumed T1D.Poster Presentations Session IV - CCardiovascular Disorders - Clinical Outcomes Studies - no. PCV27OBJECTIVES: Traditionally, researchers relied on eliciting preferences through face-to-face interviews. Recently, there has been a shift towards using alternative modes, such as the internet, to gather such data. These different modes may be a source of variation in the results. In health services research, preferences are important as they provide an estimate of the value of each quality of life state, and can be used as weights to reflect the differential utility of each state. In this study, we compare the preferences elicited from two modes of administration (internet versus face-to-face) for the best-worst scaling (BWS) technique using the Adult Social Care Outcomes Toolkit service user measure (ASCOT-S). METHODS: Data were collected from a representative sample of the general population in England. The respondents (face-to-face: n=500; online: n=1,001) completed a survey which included the BWS experiment involving the ASCOT-S, consisted of 32 tasks which were blocked into 4 segments. Multinomial logistic regressions were undertaken to analyse the data. To allow for direct comparisons between the modes, model coefficients were standardised. RESULTS: Respondents in the face-to-face survey placed lower value on the lower levels of all ASCOT-S domains, except social participation, than those in the internet survey. The highest point difference of 0.12 was observed in Level 2 of the occupation domain. For the highest level of all ASCOT-S domains, except social participation, preference weights were higher in the face-to-face survey than the internet with point differences of up to 0.10. CONCLUSIONS: This study compared utility weights obtained from a BWS exercise using two modes of administration for the ASCOTS. The findings showed variation of responses between the two modes. Most differences were not significant and were low in absolute value. This suggests that preference weights are similar across the different modes of administration. We reflect on the implications of these findings for cost-effectiveness research.

PCV 139 - Integrating patient preferences in efficiency frontier analyses using the analytical hierarchy process

Objectives: Traditional valuation methods are insensitive to small improvements in process and outcome of care. Best-Worst scaling (BWS) was proposed as a sensitive and efficient method to determine the relative value of different treatments for the same disease, which would be desirable to estimate cost-effectiveness. The study objective was to compare the ability of BWS to differentiate between different treatment alternatives to that of Time Trade Off (TTO) and Visual Analogue Scales (VAS). Methods: An online survey was conducted to estimate individual values for six different treatments reflecting the real-life options in the treatment of Parkinson’s Disease with BWS2, BWS3, TTO and VAS (n=592). Pearson correlation coefficient was used to examine the strength of linear dependence between estimated utility scores. Results: Twenty-seven percent of respondents was not willing to trade life years in TTO. Only two percent of the respondent does not differentiate between the value of health states with VAS. When non-traders were excluded from the analysis, the best case scenario was valued significantly higher than the worst case scenario with all methods. Rank reversals among intermediate alternatives were common. The correlation between utility scores was very strong (VAS-BWS2 1,0; VAS-BWS3 0.98; TTO-BWS2 0.99; TTO-BWS3 0.98, BWS2-BWS3 0.96; P<0.000, n=434). Conclusions: The results demonstrate that BWS, TTO and VAS can be used to elicit incremental utility gain of small improvements in care. However, all methods have limitations. VAS does not result in utilities and some respondents do not trade with TTO. While the use of BWS is attractive because of its ability to estimate utilities for many different treatment alternatives, its applicability in CEA is limited because BWS utilities are not anchored on a 0-1 utility scale. We propose to use TTO to estimate utility for extreme health states, and to use BWS to value intermediate health states which differ on process characteristics.

PCV96 - Acceptability of technological treatment and the effect of respondent characteristics on treatment preference

Objectives: To explore how participants evaluate and complete the choice tasks in Discrete Choice Experiments (DCE), with special attention to the impact of educational level and health literacy. Methods: Two existing DCE questionnaires on rotavirus vaccination and prostate cancer screening served as a case for the current study. In total, 70 participants were sampled based on educational level (35 per case study). During structured interviews, participants completed five choice tasks aloud. Interviewers monitored how participants read the choice tasks, how they interpreted the included risk attributes and what decision strategy they used to make their decision and if the monotonicity and continuity axioms hold. Results: The majority of the participants read all the attributes within each choice task. Nearly all participants chose the scenario with the optimal attribute levels (monotonicity axiom). In accordance with the continuity axiom, most participants mentioned three or more attributes when motivating their decisions. Overall, higher educated and literate participants more often included three or more attributes when motivating their decision and used trading between attributes more often as a decision strategy. Conclusions: The majority of the participants complete a DCE as presumed by its underlying methodology. However, the assumptions did not hold for a subset of lower educated and less literate participants. Based on participants’ age, educational level and health literacy additional measures should be undertaken to enhance participants’ understanding of the attributes, the attribute levels and the choice tasks in a DCE.

The use of multi-criteria decision methods in health care. Does method used influence outcome? [Poster]

OBJECTIVES: In comparative effectiveness research and economic evaluations, benefits of technologies are measured using multiple outcomes measures. Information lacks however about the importance of these endpoints for patients. We propose a new methodology to integrate patient weighted outcomes in a cost-efficiency frontier. We illustrate this methodology by means of an efficiency frontier analysis of five alternative treatments of patients with equinovarus deformity poststroke. METHODS: The Analytic Hierarchy Process (AHP) is a technique for multi-criteria analysis. The AHP supported 140 patients to prioritize the outcome measures of treatments of equinovarus deformity poststroke, and 10 professionals to prioritize the treatments regarding the outcome measures. These outcome measures include functional outcomes, risk and side effects, comfort, daily effort, cosmetics, and impact of the treatment. Sensitivity analysis is based on bootstrapping of the participants’ priorities. Relative costs include the device related costs and the care related costs of the treatments. RESULTS: The overall effectiveness of soft-tissue surgery (.41) is ranked first, followed by orthopedic footwear (.18), ankle-footorthosis (.15), surface electrostimulation (.14), and finally implanted electrostimulation (.12). Implanted electrostimulation (.35) and soft-tissue surgery (.34) are considered to be most expensive, followed by surface electrostimulation (.26), orthopedic footwear (.03) and ankle-foot orthosis (.02). Based on these priorities of the treatments’ overall effectiveness and costs, an efficiency frontier was drawn that includes decision uncertainty. CONCLUSIONS: The results suggest that the cost-effectiveness of implanted electrostimulation and surface electrostimulation are unfavourable. This new methodology for efficiency frontier analysis allows decision makers to integrate the outcomes about the diverse values and costs of health care technology, and can be applied broadly. It is particularly suitable in the field of early technology assessment, since the AHP supports a systematic estimation of priors about the effectiveness of alternative treatments.

PST12 THE USE OF MULTI-CRITERIA DECISION METHODS IN HEALTH CARE.WHICH METHOD IS MOST SUITABLE FOR HEALTHY AND COGNITIVELY IMPAIRED POPULATION?

OBJECTIVES: Surgical and/or technological treatment such as nerve stimulation is becoming increasingly popular in the treatment of acquired ankle-foot deformity in rehabilitation medicine. It is known that the older and impaired population can be technology adverse. The purpose of this study was to determine the acceptability of invasive technological treatment to patients and healthy controls and to study the influence of respondent characteristics on the preference for treatment. METHODS: A total of 204 Respondents participated in a conjoint analysis discrete choice experiment. Ankle-foot impairment was related to either central neurological (n = 58), or peripheral neurological disease (n = 54). Healthy respondents were also included (n = 92). The amount of information on the decision problem which was provided to the healthy controls varied. A multinomial logit regression model was used to estimate part worth utilities for the attribute levels of 8 criteria (treatment duration, treatment impact, duration and ease of use of aids, complication severity and rate, comfort & cosmetics, result type and success rate on choice of treatment) with 2–4 levels and attribute importance and to study the influence of age, gender, educational level, cognitive impairment, physical impairment and extent of information provision prior to the experiment on the fit of the regression model. RESULTS: All treatment attributes have a significant influence on treatment choice. Most important are impact of treatment (20%) and duration & ease of use of aids (19%). No operation (0.46) and minimal use of aids (0.39) is preferred. Age has a significant influence (W = 4.92; p = 0.026). No effect of cognitive impairment or ankle-foot impairment was found. CONCLUSIONS: It could be concluded that 1) surgical treatment and the use of technology are considered negative aspects of treatment, and 2) age-matched healthy respondents’ preferences can be used as predictors for cognitively and physically impaired patients.