Putting the Choice in Choice Tasks: Incorporating Preference Elicitation Tasks in Health Preference Research

Choice-based preference elicitation methods such as the discrete choice experiment (DCE) present hypothetical choices to respondents, with an expectation that these hypothetical choices accurately reflect a 'real world' health-related decision context and that consequently the choice data can be held to be a true representation of the respondent's health or treatment preferences. For this to be the case, careful consideration needs to be given to the format of the choice task in a choice experiment. The overarching aim of this paper is to highlight important aspects to consider when designing and 'setting up' the choice tasks to be presented to respondents in a DCE. This includes the importance of considering the potential impact of format (e.g. choice context, choice set presentation and size) as well as choice set content (e.g. labelled and unlabelled choice sets and inclusion of reference alternatives) and choice questions (stated choice versus additional questions designed to explore complete preference orders) on the preference estimates that are elicited from studies. We endeavoure to instil a holistic approach to choice task design that considers format alongside content, experimental design and analysis.

Patient preferences for a guided self-help programme to prevent relapse in anxiety or depression: A discrete choice experiment

BACKGROUND

Anxiety and depressive disorders are increasingly being viewed as chronic conditions with fluctuating symptom levels. Relapse prevention programmes are needed to increase self-management and prevent relapse. Fine-tuning relapse prevention programmes to the needs of patients may increase uptake and effectiveness.

MATERIALS AND METHODS

A discrete choice experiment (DCE) was conducted amongst patients with a partially or fully remitted anxiety or depressive disorder. Patients were presented 20 choice tasks with two hypothetical treatment scenarios for relapse prevention, plus a "no treatment" option. Each treatment scenario was based on seven attributes of a hypothetical but realistic relapse prevention programme. Attributes considered professional contact frequency, treatment type, delivery mode, programme flexibility, a personal relapse prevention plan, time investment and effectiveness. Choice models were estimated to analyse the data.

RESULTS

A total of 109 patients with a partially or fully remitted anxiety or depressive disorder completed the DCE. Attributes with the strongest impact on choice were high effectiveness, regular contact with a professional, low time investment and the inclusion of a personal prevention plan. A high heterogeneity in preferences was observed, related to both clinical and demographic characteristics: for example, a higher number of previous treatment episodes was related to a preference for a higher frequency of contact with a professional, while younger age was related to a stronger preference for high effectiveness.

CONCLUSIONS

This study using a DCE provides insights into preferences for a relapse prevention programme for anxiety and depressive disorders that can be used to guide the development of such a programme.

The Fold-in, Fold-out Design for DCE Choice Tasks: Application to Burden of Disease

Background In discrete-choice experiments (DCEs), choice alternatives are described by attributes. The importance of each attribute can be quantified by analyzing respondents’ choices. Estimates are valid only if alternatives are defined comprehensively, but choice tasks can become too difficult for respondents if too many attributes are included. Several solutions for this dilemma have been proposed, but these have practical or theoretical drawbacks and cannot be applied in all settings. The objective of the current article is to demonstrate an alternative solution, the fold-in, fold-out approach (FiFo). We use a motivating example, the ABC Index for burden of disease in chronic obstructive pulmonary disease (COPD). Methods Under FiFo, all attributes are part of all choice sets, but they are grouped into domains. These are either folded in (all attributes have the same level) or folded out (levels may differ). FiFo was applied to the valuation of the ABC Index, which included 15 attributes. The data were analyzed in Bayesian mixed logit regression, with additional parameters to account for increased complexity in folded-out questionnaires and potential differences in weight due to the folding status of domains. As a comparison, a model without the additional parameters was estimated. Results Folding out domains led to increased choice complexity for respondents. It also gave domains more weight than when it was folded in. The more complex regression model had a better fit to the data than the simpler model. Not accounting for choice complexity in the models resulted in a substantially different ABC Index. Conclusion Using a combination of folded-in and folded-out attributes is a feasible approach for conducting DCEs with many attributes.

Exploring the Impact of Adding a Respiratory Dimension to the EQ-5D-5L

Objectives. To evaluate the impact of adding a respiratory dimension (a bolt-on dimension) to the EQ-5D-5L health state valuations. Methods. Based on extensive regression and principal component analyses, 2 respiratory bolt-on candidates were formulated: R1, limitations in physical activities due to shortness of breath, and R2, breathing problems. Valuation interviews for the selected bolt-ons were performed with a representative sample from the Dutch general public using the standardized interview protocol and software of the EuroQol group. Hybrid models based on the combined time-tradeoff (TTO) and discrete choice experiment (DCE) data were estimated to assess whether the 5 levels of the respiratory bolt-on led to significant changes in utility values. Results. For each bolt-on candidate, slightly more than 200 valuation interviews were conducted. Mean TTO values and DCE choice probabilities for health states with a level 4 or 5 for the respiratory dimension were significantly lower compared with the same health states in the Dutch EQ-5D-5L valuation study without the respiratory dimension. Results of hybrid models showed that for the bolt-on “limitations in physical activities,” the utility decrements were significant for level 3 (–0.055), level 4 (–0.087), and level 5 (–0.135). For “breathing problems,” the utility decrements for the same levels were greater (–0.086, –0.219, and –0.327, respectively). Conclusions. The addition of each of the 2 respiratory bolt-ons to the EQ-5D-5L had a significant effect on the valuation of health states with severe levels for the bolt-on. The bolt-on dimension “breathing problems” showed the greatest utility decrements and therefore seems the most appropriate respiratory bolt-on dimension.

Attribute level overlap (and color coding) can reduce task complexity, improve choice consistency, and decrease the dropout rate in discrete choice experiments

A randomized controlled discrete choice experiment (DCE) with 3,320 participating respondents was used to investigate the individual and combined impact of level overlap and color coding on task complexity, choice consistency, survey satisfaction scores, and dropout rates. The systematic differences between the study arms allowed for a direct comparison of dropout rates and cognitive debriefing scores and accommodated the quantitative comparison of respondents' choice consistency using a heteroskedastic mixed logit model. Our results indicate that the introduction of level overlap made it significantly easier for respondents to identify the differences and choose between the choice options. As a stand-alone design strategy, attribute level overlap reduced the dropout rate by 30%, increased the level of choice consistency by 30%, and avoided learning effects in the initial choice tasks of the DCE. The combination of level overlap and color coding was even more effective: It reduced the dropout rate by 40% to 50% and increased the level of choice consistency by more than 60%. Hence, we can recommend attribute level overlap, with color coding to amplify its impact, as a standard design strategy in DCEs.

Advocating a Paradigm Shift in Health-State Valuations: The Estimation of Time-Preference Corrected QALY Tariffs

BACKGROUND

Despite evidence of nonproportional trade-offs in time trade-off exercises and the explicit incorporation of exponential discounting in health technology assessment calculations, quality-adjusted life-year (QALY) tariffs are currently still established under the assumption of linear time preferences.

OBJECTIVES

The aim of this study was to introduce a general method of accommodating for nonlinear time preferences in discrete choice experiment (DCE) duration studies and to evaluate its impact on estimated QALY tariffs.

METHODS

A parsimonious utility function is proposed that accommodates any discounting function and preserves linear time preferences as a special case. Based on an efficient DCE design and 1775 respondents from a nationally representative scientific household panel, preferences and QALY tariffs for the Dutch SF-6D were estimated while accommodating for nonlinear time preferences via exponential and hyperbolic discounting functions.

RESULTS

When the discount rate was estimated directly, we found strong evidence of nonlinear time preferences (with an exponential and hyperbolic discount rate of 5.7% and 16.5%, respectively). When the discount rate was estimated as a function of health state severity, we found that years lived in better health states are discounted minus years lived in impaired health states. Finally, the best statistical fit was obtained when using a hyperbolic discount function, which resulted in smaller QALY decrements and fewer health states classified as worse than immediate death.

CONCLUSIONS

Our results highlight the relevance and even necessity of a paradigm shift in health valuation studies in favor of time-preference corrected QALY tariffs, with potentially important implications for health technology assessment calculations and regulatory decisions.

Effect of Level Overlap and Color Coding on Attribute Non-Attendance in Discrete Choice Experiments

OBJECTIVE

The aim of this study was to test the hypothesis that level overlap and color coding can mitigate or even preclude the occurrence of attribute nonattendance in discrete choice experiments.

METHODS

A randomized controlled experiment with five experimental study arms was designed to investigate the independent and combined impact of level overlap and color coding on respondents' attribute nonattendance. The systematic differences between the study arms allowed for a direct comparison of observed dropout rates and estimates of the average number of attributes attended to by respondents, which were obtained by using augmented mixed logit models that explicitly incorporated attribute non-attendance.

RESULTS

In the base-case study arm without level overlap or color coding, the observed dropout rate was 14%, and respondents attended, on average, only two out of five attributes. The independent introduction of both level overlap and color coding reduced the dropout rate to 10% and increased attribute attendance to three attributes. The combination of level overlap and color coding, however, was most effective: it reduced the dropout rate to 8% and improved attribute attendance to four out of five attributes. The latter essentially removes the need to explicitly accommodate for attribute non-attendance when analyzing the choice data.

CONCLUSIONS

On the basis of the presented results, the use of level overlap and color coding are recommendable strategies to reduce the dropout rate and improve attribute attendance in discrete choice experiments.

Choice Defines Value: A Predictive Modeling Competition in Health Preference Research

OBJECTIVE

To identify which specifications and approaches to model selection better predict health preferences, the International Academy of Health Preference Research (IAHPR) hosted a predictive modeling competition including 18 teams from around the world.

METHODS

In April 2016, an exploratory survey was fielded: 4074 US respondents completed 20 out of 1560 paired comparisons by choosing between two health descriptions (e.g., longer life span vs. better health). The exploratory data were distributed to all teams. By July, eight teams had submitted their predictions for 1600 additional pairs and described their analytical approach. After these predictions had been posted online, a confirmatory survey was fielded (4148 additional respondents).

RESULTS

The victorious team, "Discreetly Charming Econometricians," led by Michał Jakubczyk, achieved the smallest χ², 4391.54 (a predefined criterion). Its primary scientific findings were that different models performed better with different pairs, that the value of life span is not constant proportional, and that logit models have poor predictive validity in health valuation.

CONCLUSIONS

The results demonstrated the diversity and potential of new analytical approaches in health preference research and highlighted the importance of predictive validity in health valuation.

ABC Index: quantifying experienced burden of COPD in a discrete choice experiment and predicting costs

OBJECTIVE

The Assessment of Burden of COPD (ABC) tool supports shared decision making between patient and caregiver. It includes a coloured balloon diagram to visualise patients' scores on burden indicators. We aim to determine the importance of each indicator from a patient perspective, in order to calculate a weighted index score and investigate whether that score is predictive of costs.

DESIGN

Discrete choice experiment.

SETTING AND PARTICIPANTS

Primary care and secondary care in the Netherlands. 282 patients with chronic obstructive pulmonary disease (COPD) and 252 members of the general public participated.

METHODS

Respondents received 14 choice questions and indicated which of two health states was more severe. Health states were described in terms of specific symptoms, limitations in physical, daily and social activities, mental problems, fatigue and exacerbations, most of which had three levels of severity. Weights for each item-level combination were derived from a Bayesian mixed logit model. Weights were rescaled to construct an index score from 0 (best) to 100 (worst). Regression models were used to find a classification of this index score in mild, moderate and severe that was discriminative in terms of healthcare costs.

RESULTS

Fatigue, limitations in moderate physical activities, number of exacerbations, dyspnoea at rest and fear of breathing getting worse contributed most to the burden of disease. Patients assigned less weight to dyspnoea during exercise, listlessness and limitations with regard to strenuous activities. Respondents from the general public mostly agreed. Mild, moderate and severe burden of disease were defined as scores <20, 20-39 and ≥40. This categorisation was most predictive of healthcare utilisation and annual costs: €1368, €2510 and €9885, respectively.

CONCLUSIONS

The ABC Index is a new index score for the burden of COPD, which is based on patients' preferences. The classification of the index score into mild, moderate and severe is predictive of future healthcare costs.

TRIAL REGISTRATION NUMBER

NTR3788; Post-results.

Are Health State Valuations from the General Public Biased? A Test of Health State Reference Dependency Using Self-assessed Health and an Efficient Discrete Choice Experiment

Health state valuations of patients and non-patients are not the same, whereas health state values obtained from general population samples are a weighted average of both. The latter constitutes an often-overlooked source of bias. This study investigates the resulting bias and tests for the impact of reference dependency on health state valuations using an efficient discrete choice experiment administered to a Dutch nationally representative sample of 788 respondents. A Bayesian discrete choice experiment design consisting of eight sets of 24 (matched pairwise) choice tasks was developed, with each set providing full identification of the included parameters. Mixed logit models were used to estimate health state preferences with respondents' own health included as an additional predictor. Our results indicate that respondents with impaired health worse than or equal to the health state levels under evaluation have approximately 30% smaller health state decrements. This confirms that reference dependency can be observed in general population samples and affirms the relevance of prospect theory in health state valuations. At the same time, the limited number of respondents with severe health impairments does not appear to bias social tariffs as obtained from general population samples. Copyright © 2016 John Wiley & Sons, Ltd.

Head-to-head comparison of health-state values derived by a probabilistic choice model and scores on a visual analogue scale

BACKGROUND

Health states were quantified based on discrete choice (DC) modeling and visual analogue scale (VAS) values using the five-level version of the EQ-5D (EQ-5D-5L). The aim of this study was to determine the extent of the relationship between DC derived values (indirect method) and VAS values (direct method).

METHODS

Data were collected in Canada, the United Kingdom, the Netherlands, and the United States. Respondents were asked to perform paired comparisons between two EQ-5D-5L health states for DC. In total, 400 different EQ-5D-5L states were included. After each DC task, respondents were prompted to score the two states one after another on a VAS. Intraclass correlation coefficients were calculated between DC and VAS values and illuminating graphs were designed.

RESULTS

Approximately 400 respondents participated from each country. High similarity [individual intraclass correlation coefficients (ICC) >0.85] of DC and moderate correspondence of VAS values were observed for the four countries. Cross-country comparison of DC values shows a nonlinear relationship to the VAS values.

CONCLUSION

EQ-5D-5L derived DC and VAS values show a close but nonlinear relationship. Given the obvious biases associated with the VAS, DC methods based on ordinal responses may be a better alternative.

EQ-5D in Central and Eastern Europe: 2000-2015

OBJECTIVE

Cost per quality-adjusted life year data are required for reimbursement decisions in many Central and Eastern European (CEE) countries. EQ-5D is by far the most commonly used instrument to generate utility values in CEE. This study aims to systematically review the literature on EQ-5D from eight CEE countries.

METHODS

An electronic database search was performed up to 1 July 2015 to identify original EQ-5D studies from the countries of interest. We analysed the use of EQ-5D with respect to clinical areas, methodological rigor, population norms and value sets.

RESULTS

We identified 143 studies providing 152 country-specific results with a total sample size of 81,619: Austria (n = 11), Bulgaria (n = 6), Czech Republic (n = 18), Hungary (n = 47), Poland (n = 51), Romania (n = 2), Slovakia (n = 3) and Slovenia (n = 14). Cardiovascular (21 %), neurologic (17 %), musculoskeletal (15 %) and endocrine, nutritional and metabolic diseases (13 %) were the most frequently studied clinical areas. Overall, 112 (78 %) of the studies reported EQ VAS results and 86 (60 %) EQ-5D index scores, of which 27 (31 %) did not specify the applied tariff. Hungary, Poland and Slovenia have population norms. Poland and Slovenia also have a national value set.

CONCLUSIONS

Increasing use of EQ-5D is observed throughout CEE. The spread of health technology assessment activities in countries seems to be reflected in the number of EQ-5D studies. However, improvement in informed use and methodological quality of reporting is needed. In jurisdictions where no national value set is available, in order to ensure comparability we recommend to apply the most frequently used UK tariff. Regional collaboration between CEE countries should be strengthened.

Sample Size Requirements for Discrete-Choice Experiments in Healthcare: a Practical Guide

Discrete-choice experiments (DCEs) have become a commonly used instrument in health economics and patient-preference analysis, addressing a wide range of policy questions. An important question when setting up a DCE is the size of the sample needed to answer the research question of interest. Although theory exists as to the calculation of sample size requirements for stated choice data, it does not address the issue of minimum sample size requirements in terms of the statistical power of hypothesis tests on the estimated coefficients. The purpose of this paper is threefold: (1) to provide insight into whether and how researchers have dealt with sample size calculations for healthcare-related DCE studies; (2) to introduce and explain the required sample size for parameter estimates in DCEs; and (3) to provide a step-by-step guide for the calculation of the minimum sample size requirements for DCEs in health care.

Dutch Tariff for the Five-Level Version of EQ-5D

BACKGROUND

In 2009, a new version of the EuroQol five-dimensional questionnaire (EQ-5D) was introduced with five rather than three answer levels per dimension. This instrument is known as the EQ-5D-5L. To make the EQ-5D-5L suitable for use in economic evaluations, societal values need to be attached to all 3125 health states.

OBJECTIVES

To derive a Dutch tariff for the EQ-5D-5L.

METHODS

Health state values were elicited during face-to-face interviews in a general population sample stratified for age, sex, and education, using composite time trade-off (cTTO) and a discrete choice experiment (DCE). Data were modeled using ordinary least squares and tobit regression (for cTTO) and a multinomial conditional logit model (for DCE). Model performance was evaluated on the basis of internal consistency, parsimony, goodness of fit, handling of left-censored values, and theoretical considerations.

RESULTS

A representative sample (N = 1003) of the Dutch population participated in the valuation study. Data of 979 and 992 respondents were included in the analysis of the cTTO and the DCE, respectively. The cTTO data were left-censored at -1. The tobit model was considered the preferred model for the tariff on the basis of its handling of the censored nature of the data, which was confirmed through comparison with the DCE data. The predicted values for the EQ-5D-5L ranged from -0.446 to 1.

CONCLUSIONS

This study established a Dutch tariff for the EQ-5D-5L on the basis of cTTO. The values represent the preferences of the Dutch population. The tariff can be used to estimate the impact of health care interventions on quality of life, for example, in context of economic evaluations.

Cost-effectiveness of the 'Walcheren Integrated Care Model' intervention for community-dwelling frail elderly

BACKGROUND

An important aim of integrated care for frail elderly is to generate more cost-effective health care. However, empirical research on the cost-effectiveness of integrated care for community-dwelling frail elderly is limited.

OBJECTIVE

This study reports on the cost-effectiveness of the Walcheren Integrated Care Model (WICM) after 12 months from a societal perspective.

METHODS

The design of this study was quasi-experimental. In total, 184 frail elderly patients from 3 GP practices that implemented the WICM were compared with 193 frail elderly patients of 5 GP practices that provided care as usual. Effects were determined by health-related quality of life (EQ-5D questionnaire). Costs were assessed based on questionnaires, GP files, time registrations and reports from multidisciplinary meetings. Average costs and effects were compared using t-tests. The incremental cost-effectiveness ratio (ICER) was calculated, and bootstrap methods were used to determine its reliability.

RESULTS

Neither the WICM nor care as usual resulted in a change in health-related quality of life. The average total costs of the WICM were higher than care as usual (17089 euros versus 15189 euros). The incremental effects were 0.00, whereas the incremental costs were 1970 euros, indicating an ICER of 412450 euros.

CONCLUSIONS

The WICM is not cost-effective, and the costs per quality-adjusted life year are high. The costs of the integrated care intervention do not outweigh the limited effects on health-related quality of life after 12 months. More analyses of the cost-effectiveness of integrated care for community-dwelling frail elderly are recommended as well as consideration of the specific costs and effects.

Patient and physician preferences for oral pharmacotherapy for overactive bladder: two discrete choice experiments

OBJECTIVE

We examined patient and treating physician (general practitioners, urologists, and [uro]gynecologists) preferences for oral pharmacotherapy (antimuscarinics and beta-3 adrenoceptor agonists) for overactive bladder to gain a deeper understanding of which attributes drive their treatment decision-making and to quantify to what extent.

RESEARCH DESIGN AND METHODS

Two separate discrete choice experiments were developed and validated using the input of patients and physicians. The patient experiment contained the following attributes: micturition frequency, incontinence, nocturia, urgency, dry mouth, constipation, increased heart rate, and increased blood pressure. The physician experiment contained two additional attributes: coping and atrial fibrillation. Both were fielded in five European countries. To allow for preference heterogeneity, utility functions were estimated using a mixed multinomial logit model.

RESULTS

A total of 442 patient and 318 physician responses were analyzed. Patients ranked the attributes based on their largest potential impact on treatment value as follows: incontinence, nocturia, risk of an increased heart rate, urgency, frequency, risk of increased blood pressure, risk of constipation, and risk of dry mouth; and physicians as follows: incontinence, urgency, nocturia, frequency, risk of dry mouth, coping, risk of increased heart rate, risk of increased blood pressure, risk of atrial fibrillation, and risk of constipation. CONCLUSION AND LIMITATIONS: In their valuations, physicians put more emphasis on increasing benefits, whereas patients put more emphasis on limiting risks of side effects. Another contrast that emerged was that patients' valuations of side effects were found to be fairly insensitive to the presented risk levels (with the exception of risk of dry mouth), whereas physicians' evaluated all side effects in a risk-level dependent manner. The obtained utility functions can be used to predict whether, to what extent, and for which reasons patients and physicians would choose one oral pharmacotherapy over another, as well as to advance shared decision-making.

Perspectives of Clinicians Involved in the RESTART-Study: Outcomes of a Focus Group

PURPOSE

The purpose of this study was to explore the attitudes and beliefs of speech-language pathologists (SLPs) with regard to the Lidcombe Program and Demands and Capacities-based treatment and to examine how these attitudes and beliefs might have changed as a result of participating in the RESTART-study.

METHOD

A focus group meeting with 13 SLPs was organized. The discussion was structured using questions on therapy preference, attitudes about and explicit comparison of both treatments and treatment manuals, and learnings of trial participation.

RESULTS

Four main themes were identified. First, a change in attitude toward treatment choice was observed. Second, this change was related to a change in beliefs about the potential of both treatments. Third, aspects of the treatments regarded as success factors were considered. Last, learning outcomes and increased professionalism as a result of participating in the RESTART-trial were discussed.

CONCLUSIONS

This study showed how attitudes and beliefs of SLPs with regard to the Lidcombe Program and Demands and Capacities-based treatment evolved during a randomized trial. This work increases our understanding of the role of attitudes and beliefs in the uptake and utilization of therapies and demonstrates the importance of collecting qualitative data. Results and recommendations should prove of value in implementing the RESTART-trial results and in training SLPs.

What Influences Patients' Decisions When Choosing a Health Care Provider? Measuring Preferences of Patients with Knee Arthrosis, Chronic Depression, or Alzheimer's Disease, Using Discrete Choice Experiments

OBJECTIVE

To investigate what influences patients' health care decisions and what the implications are for the provision of information on the quality of health care providers to patients.

DATA SOURCES/STUDY SETTING

Dutch patient samples between November 2006 and February 2007.

STUDY DESIGN

Discrete choice experiments were conducted in three patient groups to explore what influences choice for health care providers.

DATA COLLECTION

Data were obtained from 616 patients with knee arthrosis, 368 patients with chronic depression, and 421 representatives of patients with Alzheimer's disease.

PRINCIPAL FINDINGS

The three patients groups chose health care providers on a different basis. The most valued attributes were effectiveness and safety (knee arthrosis); continuity of care and relationship with the therapist (chronic depression); and expertise (Alzheimer's disease). Preferences differed between subgroups, mainly in relation to patients' choice profiles, severity of disease, and some background characteristics.

CONCLUSIONS

This study showed that there is substantial room for (quality) information about health care providers in patients' decision processes. This information should be tailor-made, targeting specific patient segments, because different actors and factors play a part in their search and selection process.

Health-related quality of life of preschool children who stutter

PURPOSE

The purpose of this study is to compare the health-related quality of life (HrQoL) of preschool children who stutter (CWS) and a reference population of children who do not stutter, and to evaluate the association between stuttering severity and HrQoL.

METHODS

Baseline data were used from 197 children participating in a multicenter Randomized Clinical Trial in the Netherlands. Information on stuttering severity and time since onset (TSO) of stuttering was obtained from the baseline evaluation by speech- and language therapists. Stuttering severity was measured using the SSI-3. HrQoL was assessed using proxy versions of two Child Health Questionnaires (ITQOL-97 and CHQ-PF28), the Health Utility Index 3 (HUI3) and the EuroQoL EQ-VAS (EQ-VAS).

RESULTS

While the outcomes on the EQ-VAS and the HUI3 showed that the HrQoL of CWS is slightly poorer than that of the Dutch reference population, results on the different dimensions of the CHQ-instruments did not reveal any difference in scores between stuttering children and reference groups. Within the group of CWS, two ITQOL-97 and four CHQ-PF28 scales showed statistically different scores for children in different SSI stuttering severity or TSO categories. However, the effect sizes showed that these differences were so small that they could be considered negligible.

CONCLUSION

The results of this study do not reveal a diminished HrQoL for preschool CWS. Future research should include a larger cohort of children with severe stuttering, study the longitudinal course of HrQoL and incorporate additional parameters such as the characteristics of the child and his environment.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) summarize the current evidence base on HrQoL in people who stutter; (b) describe the HrQoL of preschool CWS on different HrQoL measures; (c) describe the relationship between stuttering severity and HrQoL in preschool CWS.

Quality of life instruments for economic evaluations in health and social care for older people: a systematic review

Gaining health may not be the main goal of healthcare services aimed at older people, which may (also) seek to improve wellbeing. This emphasizes the need of finding appropriate outcome measures for economic evaluation of such services, particularly in long-term care, capturing more than only health-related quality of life (HrQol). This review assesses the usefulness of HrQol and wellbeing instruments for economic evaluations specifically aimed at older people, focusing on generic and preference-based questionnaires measuring wellbeing in particular. We systematically searched six databases and extracted instruments used to assess HrQol and wellbeing outcomes. Instruments were compared based on their usefulness for economic evaluation of services aimed at older people (dimensions measured, availability of utility scores, extent of validation). We identified 487 articles using 34 generic instruments: 22 wellbeing (two of which were preference-based) and 11 HrQol instruments. While standard HrQol instruments measure physical, social and psychological dimensions, wellbeing instruments contain additional dimensions such as purpose in life and achievement, security, and freedom. We found four promising wellbeing instruments for inclusion in economic evaluation: Ferrans and Powers QLI and the WHO-Qol OLD, ICECAP-O and the ASCOT. Ferrans and Powers QLI and the WHO-Qol OLD are widely validated but lack preference-weights while for ICECAP-O and the ASCOT preference-weights are available, but are less widely validated. Until preference-weights are available for the first two instruments, the ICECAP-O and the ASCOT currently appear to be the most useful instruments for economic evaluations in services aimed at older people. Their limitations are that (1) health dimensions may be captured only partially and (2) the instruments require further validation. Therefore, we currently recommend using the ICECAP-O or the ASCOT alongside the EQ-5D or SF-6D when evaluating interventions aimed at older people.

Dealing with the health state 'dead' when using discrete choice experiments to obtain values for EQ-5D-5L heath states

OBJECTIVE

To evaluate two different methods to obtain a dead (0)--full health (1) scale for EQ-5D-5L valuation studies when using discrete choice (DC) modeling.

METHOD

The study was carried out among 400 respondents from Barcelona who were representative of the Spanish population in terms of age, sex, and level of education. The DC design included 50 pairs of health states in five blocks. Participants were forced to choose between two EQ-5D-5L states (A and B). Two extra questions concerned whether A and B were considered worse than dead. Each participant performed ten choice exercises. In addition, values were collected using lead-time trade-off (lead-time TTO), for which 100 states in ten blocks were selected. Each participant performed five lead-time TTO exercises. These consisted of DC models offering the health state 'dead' as one of the choices--for which all participants' responses were used (DCdead)--and a model that included only the responses of participants who chose at least one state as worse than dead (WTD) (DCWTD). The study also estimated DC models rescaled with lead-time TTO data and a lead-time TTO linear model.

RESULTS

The DC(dead) and DCWTD models produced relatively similar results, although the coefficients in the DCdead model were slightly lower. The DC model rescaled with lead-time TTO data produced higher utility decrements. Lead-time TTO produced the highest utility decrements.

CONCLUSIONS

The incorporation of the state 'dead' in the DC models produces results in concordance with DC models that do not include 'dead'.

Time to tweak the TTO: results from a comparison of alternative specifications of the TTO

This article examines the effect that different specifications of the time trade-off (TTO) valuation task may have on values for EQ-5D-5L health states. The new variants of the TTO, namely lead-time TTO and lag-time TTO, along with the classic approach to TTO were compared using two durations for the health states (15 and 20 years). The study tested whether these methods yield comparable health-state values. TTO tasks were administered online. It was found that lag-time TTO produced lower values than lead-time TTO and that the difference was larger in the longer time frame. Classic TTO values most resembled those of the lag-time TTO in a 20-year time frame in terms of mean absolute difference. The relative importance of different domains of health was systematically affected by the duration of the health state. In the tasks with a 10-year health-state duration, anxiety/depression had the largest negative impact on health-state values; in the tasks with a 5-year duration, the pain/discomfort domain had the largest negative impact.

The effects of lead time and visual aids in TTO valuation: a study of the EQ-VT framework

BACKGROUND

The effect of lead time in time trade-off (TTO) valuation is not well understood. The purpose of this study was to investigate the effects on health-state valuation of the length of lead time and the way the lead-time TTO task is displayed visually.

METHODS

Using two general population samples, we compared three lead-time TTO variants: 10 years of lead time in full health preceding 5 years of unhealthy time (standard); 5 years of lead time preceding 5 years of unhealthy time (experimental); and 10 years of lead time and 5 years of unhealthy time, presented with a visual aid to highlight the point where the lead time ends (experimental). Participants were randomized to receive one of the lead-time variants, as administered by a computer software program.

RESULTS

Health-state values generated by TTO valuation tasks using a longer lead time were slightly lower than those generated by tasks using a shorter lead time. When lead time and unhealthy time were presented with visual aids highlighting the difference between the lead time and unhealthy time, respondents spent more time considering health states with a value close to 0.

CONCLUSIONS

Different lead-time time trade-off variants should be carefully studied in order to achieve the best measurement of health-state values using this new method.

Introducing the composite time trade-off: a test of feasibility and face validity

INTRODUCTION

This study was designed to test the feasibility and face validity of the composite time trade-off (composite TTO), a new approach to TTO allowing for a more consistent elicitation of negative health state values.

METHODS

The new instrument combines a conventional TTO to elicit values for states regarded better than dead and a lead-time TTO for states worse than dead.

RESULTS

A total of 121 participants completed the composite TTO for ten EQ-5D-5L health states. Mean values ranged from -0.104 for health state 53555 to 0.946 for 21111. The instructions were clear to 98 % of the respondents, and 95 % found the task easy to understand, indicating feasibility. Further, the average number of steps taken in the iteration procedure to achieve the point of indifference in the TTO and the average duration of each task were indicative of a deliberate cognitive process.

CONCLUSION

Face validity was confirmed by the high mean values for the mild health states (>0.90) and low mean values for the severe states (<0.42). In conclusion, this study demonstrates the feasibility and face validity of the composite TTO in a face-to-face standardized computer-assisted interview setting.

Time trade-off: one methodology, different methods

There is no scientific consensus on the optimal specification of the time trade-off (TTO) task. As a consequence, studies using TTO to value health states may share the core element of trading length of life for quality of life, but can differ considerably on many other elements. While this pluriformity in specifications advances the understanding of TTO from a methodological point of view, it also results in incomparable health state values. Health state values are applied in health technology assessments, and in that context comparability of information is desired. In this article, we discuss several alternative specifications of TTO presented in the literature. The defining elements of these specifications are identified as being either methodological, procedural or analytical in nature. Where possible, it is indicated how these elements affect health state values (i.e., upward or downward). Finally, a checklist for TTO studies is presented, which incorporates a list of choices to be made by researchers who wish to perform a TTO task. Such a checklist enables other researchers to align methodologies in order to enhance the comparability of health state values.

Lead time TTO: leading to better health state valuations?

Preference elicitation tasks for better than dead (BTD) and worse than dead (WTD) health states vary in the conventional time trade-off (TTO) procedure, casting doubt on uniformity of scale. 'Lead time TTO' (LT-TTO) was recently introduced to overcome the problem. We tested different specifications of LT-TTO in comparison with TTO in a within-subject design. We elicited preferences for six health states and employed an intertemporal ranking task as a benchmark to test the validity of the two methods. We also tested constant proportional trade-offs (CPTO), while correcting for discounting, and the effect of extending the lead time if a health state is considered substantially WTD. LT-TTO produced lower values for BTD states and higher values for WTD states. The validity of CPTO varied across tasks, but it was higher for LT-TTO than for TTO. Results indicate that the ratio of lead time to disease time has a greater impact on results than the total duration of the time frame. The intertemporal ranking task could not discriminate between TTO and LT-TTO.

Balancing equity and efficiency in the Dutch basic benefits package using the principle of proportional shortfall

Economic evaluations are increasingly used to inform decisions regarding the allocation of scarce health care resources. To systematically incorporate societal preferences into these evaluations, quality-adjusted life year gains could be weighted according to some equity principle, the most suitable of which is a matter of frequent debate. While many countries still struggle with equity concerns for priority setting in health care, the Netherlands has reached a broad consensus to use the concept of proportional shortfall. Our study evaluates the concept and its support in the Dutch health care context. We discuss arguments in the Netherlands for using proportional shortfall and difficulties in transitioning from principle to practice. In doing so, we address universal issues leading to a systematic consideration of equity concerns for priority setting in health care. The article thus has relevance to all countries struggling with the formalization of equity concerns for priority setting.

Condition-specific preference-based measures: benefit or burden?

OBJECTIVES

Some argue that generic preference-based measures (PBMs) are not sensitive to certain disease-specific improvements. To overcome this problem, new condition-specific PBMs (CS-PBMs) are being developed, but it is not yet clear how such measures compare with existing generic PBMs.

METHOD

We generated CS-PBMs from three condition-specific questionnaires (Health Assessment Questionnaire for arthritis, Quality of Life Questionnaire for Cancer 30 for cancer, and Multiple Sclerosis Impact Scale 29 for multiple sclerosis). First, the questionnaires were reduced in content, and then, a time trade-off study was conducted in the general public (N = 402) to obtain weights associated with the dimensions and levels of the new questionnaire. Finally, we compared utilities obtained by using the CS-PBMs with utilities obtained by using the EuroQol five-dimensional (EQ-5D) questionnaire in four data sets.

RESULTS

Utility values generated by the CS-PBMs were higher than those of the EQ-5D questionnaire. The Health Assessment Questionnaire-based measure for arthritis proved to be insensitive to comorbidities. Measures based on the Multiple Sclerosis Impact Scale 29 and the Quality of Life Questionnaire for Cancer 30 discriminated comorbidities and side effect equally well as the EQ-5D questionnaire and were more sensitive than the EQ-5D questionnaire for mild impairments.

CONCLUSIONS

The introduction of PBMs that are specific to a certain disease may have the merit of sensitivity to disease-specific effects of interventions. That gain, however, is traded off to the loss of comparability of utility values and, in some cases, insensitivity to side effects and comorbidity. The use of a CS-PBM for cost-utility analysis is warranted only under strict conditions.

Mapping QLQ-C30, HAQ, and MSIS-29 on EQ-5D

Background

Responses on condition-specific instruments can be mapped on the EQ-5D to estimate utility values for economic evaluation. Mapping functions differ in predictive quality, and not all condition-specific measures are suitable for estimating EQ-5D utilities. We mapped QLQ-C30, HAQ, and MSIS-29 on the EQ-5D and compared the quality of the mapping functions with statistical and clinical indicators.

Methods

We used 4 data sets that included both the EQ-5D and a condition-specific measure to develop ordinary least squares regression equations. For the QLQ-C30, we used a multiple myeloma data set and a non-Hodgkin lymphoma one. An early arthritis cohort was used for the HAQ, and a cohort of patients with relapsing remitting or secondary progressive multiple sclerosis was used for the MSIS-29. We assessed the predictive quality of the mapping functions with the root mean square error (RMSE) and mean absolute error (MAE) and the ability to discriminate among relevant clinical subgroups. Pearson correlations between the condition-specific measures and items of the EQ-5D were used to determine if there is a relationship between the quality of the mapping functions and the amount of correlated content between the used measures.

Results

The QLQ-C30 had the highest correlation with EQ-5D items. Average %RMSE was best for the QLQ-C30 with 10.9%, 12.2% for the HAQ, and 13.6% for the MSIS-29. The mappings predicted mean EQ-5D utilities without significant differences with observed utilities and discriminated between relevant clinical groups, except for the HAQ model.

Conclusions

The preferred mapping functions in this study seem suitable for estimating EQ-5D utilities for economic evaluation. However, this research shows that lower correlations between instruments lead to less predictive quality. Using additional validation tests besides reporting statistical measures of error improves the assessment of predictive quality.

The cost-effectiveness of an intensive treatment protocol for severe dyslexia in children

Studies of interventions for dyslexia have focused entirely on outcomes related to literacy. In this study, we considered a broader picture assessing improved quality of life compared with costs. A model served as a tool to compare costs and effects of treatment according to a new protocol and care as usual. Quality of life was measured and valued by proxies using a general quality-of-life instrument (EQ-5D). We considered medical cost and non-medical cost (e.g. remedial teaching). The model computed cost per successful treatment and cost per quality adjusted life year (QALY) in time. About 75% of the total costs was related to diagnostic tests to distinguish between children with severe dyslexia and children who have reading difficulties for other reasons. The costs per successful treatment of severe dyslexia were €36 366. Successful treatment showed a quality-of-life gain of about 11%. At primary school, the average cost per QALY for severe dyslexia amounted to €58 647. In the long term, the cost per QALY decreased to €26 386 at secondary school and €17 663 thereafter. The results of this study provide evidence that treatment of severe dyslexia is cost-effective when the investigated protocol is followed.

The health care burden and societal impact of acute otitis media in seven European countries: results of an Internet survey

This paper estimates medical resource use, direct costs, and productivity losses and costs (indirect costs) during episodes of acute otitis media (AOM) in young children. A 24-item Internet questionnaire was developed for parents in Belgium (Flanders), France, Germany, Italy, The Netherlands, Spain, and the United Kingdom (UK) to report health care resource use and productivity losses during the most recent episode of AOM in their child, younger than 5 years. The percentage who did not seek medical help for AOM was considerable in The Netherlands (28.3%) and the UK (19.7%). Antibiotic use was high, ranging from 60.8% (Germany) to 87.1% (Italy). Total costs per AOM episode ranged from €332.00 (The Netherlands) to €752.49 (UK). Losses in productivity accounted for 61% (France) to 83% (Germany) of the total costs. AOM poses a significant medical and economic burden to society.

Mapping onto Eq-5 D for patients in poor health

BACKGROUND

An increasing amount of studies report mapping algorithms which predict EQ-5 D utility values using disease specific non-preference-based measures. Yet many mapping algorithms have been found to systematically overpredict EQ-5 D utility values for patients in poor health. Currently there are no guidelines on how to deal with this problem. This paper is concerned with the question of why overestimation of EQ-5 D utility values occurs for patients in poor health, and explores possible solutions.

METHOD

Three existing datasets are used to estimate mapping algorithms and assess existing mapping algorithms from the literature mapping the cancer-specific EORTC-QLQ C-30 and the arthritis-specific Health Assessment Questionnaire (HAQ) onto the EQ-5 D. Separate mapping algorithms are estimated for poor health states. Poor health states are defined using a cut-off point for QLQ-C30 and HAQ, which is determined using association with EQ-5 D values.

RESULTS

All mapping algorithms suffer from overprediction of utility values for patients in poor health. The large decrement of reporting 'extreme problems' in the EQ-5 D tariff, few observations with the most severe level in any EQ-5 D dimension and many observations at the least severe level in any EQ-5 D dimension led to a bimodal distribution of EQ-5 D index values, which is related to the overprediction of utility values for patients in poor health. Separate algorithms are here proposed to predict utility values for patients in poor health, where these are selected using cut-off points for HAQ-DI (> 2.0) and QLQ C-30 (< 45 average of QLQ C-30 functioning scales). The QLQ-C30 separate algorithm performed better than existing mapping algorithms for predicting utility values for patients in poor health, but still did not accurately predict mean utility values. A HAQ separate algorithm could not be estimated due to data restrictions.

CONCLUSION

Mapping algorithms overpredict utility values for patients in poor health but are used in cost-effectiveness analyses nonetheless. Guidelines can be developed on when the use of a mapping algorithms is inappropriate, for instance through the identification of cut-off points. Cut-off points on a disease specific questionnaire can be identified through association with the causes of overprediction. The cut-off points found in this study represent severely impaired health. Specifying a separate mapping algorithm to predict utility values for individuals in poor health greatly reduces overprediction, but does not fully solve the problem.

Preferences for long-term care services: willingness to pay estimates derived from a discrete choice experiment

Ageing populations increase pressure on long-term care. Optimal resource allocation requires an optimal mix of care services based on costs and benefits. Contrary to costs, benefits remain largely unknown. This study elicits preferences in the general elderly population for long-term care services for varying types of patients. A discrete choice experiment was conducted in a general population subsample aged 50-65 years (N = 1082) drawn from the Dutch Survey Sampling International panel. To ascertain relative preferences for long-term care and willingness to pay for these, participants were asked to choose the best of two care scenarios for four groups of hypothetical patients: frail and demented elderly, with and without partner. The scenarios described long-term care using ten attributes based on Social Production Function theory: hours of care, organized social activities, transportation, living situation, same person delivering care, room for individual preferences, coordination of services, punctuality, time on waiting list, and co-payments. We found the greatest value was attached to same person delivering care and transportation services. Low value was attached to punctuality and room for individual preferences. Nursing homes were generally considered to be detrimental for well-being except for dementia patients without a partner. Overall, long-term care services were thought to produce greatest well-being for the patients 'without a partner' and those 'with dementia'. Individuals combining these two risk factors would benefit the most from all services except transportation which was considered more important for the frail elderly. The results support the notion that long-term care services represent different value for different types of patients and that the value of a service depends upon the social context. Examination of patient profiles confirmed the notion that physical, mental and social vulnerability affect valuation of the services. Policy-making would profit from allocation models in which budgetary requirements of different services can be balanced against the well-being they produce for individuals.

Role of health technology assessment in shaping the benefits package in The Netherlands

In many countries of the Western world, the role of health technology assessment (HTA) in funding decisions of medical technologies is increasing. HTAs are expected to support decision-makers in delineating the collectively funded benefits package. To maximize their potential, it is essential that assessments are valid, reliable and timely, and that it is transparent how information provided in assessments is used in decision-making. Against this background, this article aims to review the current state of affairs regarding the use of HTA in the area of medical specialist care in The Netherlands and to evaluate strengths and weaknesses of the HTA-based system for priority setting. The reason to do so was the introduction of a new hospital financing system in The Netherlands, which allowed for expansion of the HTA system that already existed for pharmaceuticals to medical specialist care. A comprehensive account of the HTA system for medical specialist care was created using the so-called Hutton framework, followed by an exploration of its strengths and weaknesses. An important lesson to be learned from the early Dutch experiences with HTA in the area of medical specialist care is that the nature and complexity of health technologies in this area create practical problems regarding the amount and quality of available data needed to make the HTA-based system work. This hampers an unambiguous interpretation of assessment data and thus calls for stronger requirements regarding transparency and stakeholder participation. Future work focusing on the role of HTA in funding decisions is needed to provide insights in best practices for HTA systems in circumstances where a delicate balance needs to be achieved between promoting innovation, supporting effective and timely decision-making and preventing the coverage of technologies that represent a waste of resources.

Equity in health care prioritisation: an empirical inquiry into social value

The value of QALY gains for different patients may be recalculated using equity weights, but it is unclear which interpretation of equity should be used: severity of illness, fair innings or proportional shortfall. We set up an experiment to analyze which of these equity concepts best reflects people's distributional preferences. Sixty respondents assigned a priority rank to the treatment of 10 conditions using the paired comparison technique. We described these real-life conditions by their actual QALY profiles, i.e. in terms of age, disease free period, duration of disease, quality of life, and life years lost. Next we determined the priority rank order of the 10 conditions by the three equity concepts, using the weights that each equity concept attributes to the different units of the QALY profile describing the 10 conditions. To explore the social interpretation of equity, we compared the observed and theoretical rank orderings using Spearman correlations. All correlations were significant at a 0.05 level. Fair innings best predicted the observed rank order of the 10 conditions (r=0.95). Weaker correlations were found for proportional shortfall (r=0.82) and severity of illness (r=-0.65). This result calls attention to health policy, because actual health care decisions often reflect concerns of severity of illness. This raises the question if health care decision makers evaluate the claims of different patients for health care by appropriate criteria.

The "health benefit basket" in the Netherlands

This contribution describes the entitlements in Dutch health care and explores how these entitlements are determined and to whom they apply. The focus is on services of curative care. No comprehensive positive or negative list of individual services is included in formal laws. Instead, the legislation states only what general types of medical services are covered and generally the "usual care" criterion determines to which interventions patients are entitled. This criterion is not very restrictive and yields local variations in service provision, which are moderated by practice guidelines. It is conceivable, however, that the recent introduction of the DBC financing system will change the reimbursement and therefore benefit-setting policy.

Acceptability of less than perfect health states

Health normally deteriorates beyond a certain age. This means, in Amartya Sen's terms, that one's health capabilities decline beyond a certain age, making it more difficult to achieve functionings such as mobility or sexual activity. In this paper, we investigate whether this normal reduction in quality of life also induces less than perfect health states to be considered acceptable at advanced stages of life. In other words, we investigate whether it is considered acceptable that health capabilities decline over time. In this study, we use domain-specific descriptions of health (mostly following the EQ-5D domains) in order to investigate whether the acceptability of less than perfect health states is similar for all types of health losses. Besides a theoretical consideration of this issue, we present some empirical evidence based on the answers of 226 respondents to a web-based survey. The results show that often individuals do indeed consider less than perfect health states acceptable, especially at more advanced stages of life. Mild health problems are more often considered acceptable than severe health problems. The acceptability of health states is related to the quality of life score of these states, i.e., worse states are considered less acceptable. This may have implications for the allocation of scarce health care resources.

Criteria for determining a basic health services package. Recent developments in The Netherlands

The criterion of medical need figures prominently in the Dutch model for reimbursement decisions as well as in many international models for health care priority setting. Nevertheless the conception of need remains too vague and general to be applied successfully in priority decisions. This contribution explores what is wrong with the proposed definitions of medical need and identifies features in the decision-making process that inhibit implementation and usefulness of this criterion. In contrast to what is commonly assumed, the problem is not so much a failure to understand the nature of the medical need criterion and the value judgments involved. Instead the problem seems to be a mismatch between the information regarding medical need and the way in which these concerns are incorporated into policy models. Criteria--medical need, as well as other criteria such as effectiveness and cost-effectiveness--are usually perceived as "hurdles," and each intervention can pass or fail assessment on the basis of each criterion and therefore be included or excluded from public funding. These models fail to understand that choices are not so much between effective and ineffective treatments, or necessary and unnecessary ones. Rather, choices are often between interventions that are somewhat effective and/or needed. Evaluation of such services requires a holistic approach and not a sequence of fail or pass judgments. To improve applicability of criteria that pertain to medical need we therefore suggest further development of these criteria beyond their original binary meaning and propose meaningful ways in which these criteria can be integrated into policy decisions.

Diabetic foot ulcers and amputations: estimates of health utility for use in cost-effectiveness analyses of new treatments

OBJECTIVES

Diabetic foot ulcers (DFU), infections and amputations are associated with high costs of care and loss of health. To evaluate new treatments, both the extra costs incurred and the health utility gained need to be examined. However, evaluations of treatments in diabetes are hampered by the lack of utility values for health states such as DFU. We estimated utility values for health states seen amongst DFU patients.

METHODS

We identified 13 unique health states based on presence/type of DFU and amputation. Members of the general public (n=107) received a description of each health state. They were then asked to indicate how undesirable each health state was (using the time trade-off method). Each answer was then transformed to create a value representing the "utility" of the health state, the utility value represented on a 0-1 scale.

RESULTS

Valid responses could be obtained from 96 persons. Mean values included: 0.84 (diabetes with no DFU or amputation), 0.75 (uninfected DFU, no amputation), 0.68 (no DFU, previous foot amputation), and 0.63 (uninfected DFU, previous amputation of other foot). The impact of an ulcer depended on amputation status.

CONCLUSIONS

Our values correspond with previously published results but are more detailed. In addition, since our values were derived from the general public, economic evaluations that incorporate them will use the generally preferred societal perspective. Therefore, these values are appropriate, practical and sensitive weights to calculate QALYs for cost-effectiveness analyses of foot ulcer treatments.

Short term and long term health related quality of life after congenital anorectal malformations and congenital diaphragmatic hernia

AIMS

To examine short term and long term health related quality of life (HRQoL) of survivors of congenital anorectal malformations (ARM) and congenital diaphragmatic hernia (CDH), and to compare these patients' HRQoL with that of the general population.

METHODS

HRQoL was measured in 286 ARM patients and 111 CDH patients. All patients were administered a symptom checklist and a generic HRQoL measure. For the youngest children (aged 1-4) the TAIQOL (a preliminary version of the TAPQOL) was used, for the other children (aged 5-15) the TACQOL questionnaire, and for adults (aged >16) the SF-36.

RESULTS

As appeared from the symptom checklists, many patients remained symptomatic into adulthood. In the youngest ARM patients (aged 1-4 years), generic HRQoL was severely affected, but the older ARM patients showed better HRQoL. In the CDH patients, the influence of symptoms on HRQoL seemed less profound. The instruments we used revealed little difference between adults treated for ARM or CDH and the general population.

CONCLUSIONS

These results show that for two neonatal surgical procedures, improved survival does not come at the expense of poor HRQoL in adults. Even though there is considerable suffering in terms of both morbidity and mortality in the youngest group, the ultimate prognosis of survivors of the two studied congenital malformations is favourable. This finding can be used to reassure parents of patients in need of neonatal surgery for one of these conditions about the prospects for their child.

Reconciliation of economic concerns and health policy: illustration of an equity adjustment procedure using proportional shortfall

Economic evaluations have become an important and much used tool in aiding decision makers in deciding on reimbursement or implementation of new healthcare technologies. Nevertheless, the impact of economic evaluations on reimbursement decisions has been modest; results of economic evaluations do not have a good record in predicting funding decisions. This is usually explained in terms of fairness; there is increasing awareness that valuations of QALYs may differ when the QALYs accrue to different patients. The problem, however, is that these equity concerns often remain implicit, and therefore frustrate explicitness and transparency in evidence-based decision making. It has been suggested that a so-called equity adjustment procedure may (partially) solve this problem. Typically this would involve the application of so-called equity weights, which can be used to recalculate the value of QALY gains for different patients. This paper explores such an equity adjustment procedure, using the equity concept of proportional shortfall. Proportional shortfall assumes that measurement of inequalities in health should concentrate on the fraction of QALYs that people lose relative to their remaining life expectancy, and not on the absolute number of QALYs lost or gained. It is the ratio of QALYs lost over the QALYs remaining. This equity concept combines elements of two popular but conflicting notions of equity: fair innings and severity-of-illness. We applied the concept of proportional shortfall to ten conditions and tentatively explored how an equity adjustment procedure using proportional shortfall might affect priority setting. Our equity adjustment procedure lowered the cost-effectiveness threshold when a condition was relatively mild. Because the proportional shortfall caused by the ten conditions differed considerably, the equity-adjustment procedure discriminated strongly between the ten conditions, and this experiment provided a good opportunity to explore the impact of equity adjustment for healthcare reimbursement decisions. In conclusion, our results suggest that equity can be measured and that integration of equity concerns into an economic evaluation improves the fit between economic models and reimbursement decisions. It is recommended that cost-effectiveness driven health policy systems consider equity adjustments.

Validity and feasibility of the use of condition-specific outcome measures in economic evaluation

BACKGROUND

Usually, generic questionnaires such as the EQ-5D or Health Utility Index (HUI) are used to obtain utility scores for computing QALYs. Sometimes, however, application of these instruments is not possible, or the responsiveness is doubted. An alternative strategy is to attribute utility scores to health states of a condition-specific outcomes measure (CSOM). We explored the validity and feasibility of this strategy.

RESEARCH DESIGN

Our samples determined utility scores for the health states of the International Index of Erectile Function (IIEF) using time tradeoff (TTO). To reduce costs and time, the general population (n = 169) was interviewed in groups. We tested the validity of the group sessions in students. To test the extent of agreement between values obtained using the group and those obtained through individual administration, 63 students were interviewed individually and 54 in groups.

RESULTS

The utility scores for the disease-specific health states showed good construct validity. Also, the criterion validity of the adapted TTO was confirmed.

DISCUSSION

Disease-specific utility scores can be used in QALY analysis by converting them to a generic scale. Efforts should be undertaken to prevent response spreading. Administrating TTO in groups could reduce the time and costs of TTO administration and render the strategy of determining utilities for condition-specific health states more feasible.

Are patients and the general public like-minded about the effect of erectile dysfunction on quality of life?

OBJECTIVES

To substantiate claims for treatment, patients may overestimate treatment effects. Consequently, in funding debates, the question becomes whether the general public agrees on the value of a treatment. Unfortunately, little is known about the social values for treatments of erectile dysfunction (ED). To solve this problem, we compared the values of patients and the general population for ED.

METHODS

One hundred six ED patients and a representative sample of 169 individuals of the general population valued 28 health states of ED using time tradeoff. A hesitation to reveal preferences for this taboo subject or unawareness of the quality-of-life effects of ED may bias the social values. To explore the validity, we compared the factor structure of the valuation space of patients' and social values using a multivariate analysis of variance repeated measure analysis. Furthermore, we analyzed whether social values were related to demographic or sexual variables.

RESULTS

Patients valued ED lower than the general public, but the factor structure was the same. This evidence suggests that patients and the general public valued the health states of ED in the same way, although the overall level of appreciation differed slightly. Values were not systematically related to any other background variable.

CONCLUSIONS

Both patients and the general population consider erectile function an important aspect of quality of life. Therefore, funding for ED treatment might be considered. Moreover, because the value for erectile function was equivalent in different age groups, there is no convincing argument to limit funding to young patients.

['Necessity' determined on the basis of disease severity when prioritising health care interventions]

In the Netherlands, the Priorities in Healthcare [Keuzen in de Zorg] Committee proposed that the prioritisation of healthcare interventions should in part be based on the criterion 'necessity'. However, this criterion has hardly ever been used. It was proposed that 'necessity' should be defined in terms of disease severity. This concept examines the fraction of expected quality-adjusted life years (QALY) that a patient will lose if the condition concerned is not treated. The following two possible applications for healthcare policy were studied. Firstly, relatively necessary care could be fully reimbursed, whereas less necessary care would only be reimbursed in part. Secondly, for relatively necessary interventions a lower cost-effectiveness threshold (relatively high costs per QALY for necessary care) could be accepted. In these cases the concept of disease severity provides a new feasible interpretation of the criterion 'necessity'.

The valuation of the International Prostate Symptom Score (IPSS) for use in economic evaluations

OBJECTIVE

Lower Urinary Tract Symptoms (LUTS) suggestive of Benign Prostatic Obstruction (BPO) cause a reduction in quality of life, but the magnitude of that reduction cannot be estimated empirically. This is because survey instruments currently available merely sum the symptoms found, but do not value their impact on quality of life. It is therefore difficult to determine whether the effects of treatments for LUTS suggestive of BPO justify the costs. This complicates economic evaluations.

METHODS

We valued the impact on quality of life of patients with LUTS suggestive of BPO, by valuing health states defined by the International Prostate Symptom Score (IPSS) using the time trade-off (TTO). TTO values ranged from 1.0 for perfect health to 0.0 for the value of death, and can be used to calculate Quality-Adjusted Life Years (QALYs), the preferred outcome measure in health economics.

RESULTS

We reduced the number of health states defined by the IPSS using factor analysis. The resulting nine health states were valued by a representative sample of the general public (N=170) using TTO. The worst IPSS health state was valued at 0.87.

CONCLUSION

The values for health states defined by the IPSS revealed that LUTS suggestive of BPO has a mild impact on quality of life. The valuation of the IPSS facilitates economic evaluations of treatments for LUTS suggestive of BPO, because QALYs (the preferred outcome measure in health economics) can be determined empirically.

The cost-effectiveness of treatment for congenital diaphragmatic hernia

BACKGROUND/PURPOSE

The cost-effectiveness of medical interventions is becoming an important issue for decision makers. Until recently, evidence of the cost-effectiveness of neonatal surgery was largely lacking. The authors analyzed the cost-effectiveness of neonatal surgery and subsequent treatment for congenital diaphragmatic hernia (CDH).

METHODS

Both costs incurred inside and outside the health care sector (eg, out-of-pocket expenses and productivity losses) were included. Quality-adjusted life years (QALYs) were measured using the EuroQol EQ-5D questionnaire. Descriptive quality-of-life data were collected using a disease-specific questionnaire. Both costs and effects basically were measured in a life-time setting.

RESULTS

Total costs of treatment average euro 42,658, mainly consisting of costs of the initial hospitalization. Productivity losses in both the patients and their caregivers appear to be minor. Treated CDH patients, even adults, suffer from respiratory difficulties and stomach aches. According to the EQ-5D, however, their quality of life does not differ from the general population, suggesting that these symptoms barely affect overall quality of life. Treatment results in a gain of 17.5 QALYs. Costs per QALY amount to euro 2,434.

CONCLUSIONS

Treatment for CDH has favorable cost-effectiveness. Considering the growing importance of cost-effective medicine, these are important and encouraging results. Health economics outlines the inevitability of making choices that directly affect patient care and places relative values on different health care programs. The results of this study provide convincing evidence that treatment for CDH is indeed cost effective.