Deleting 'irrational' responses from discrete choice experiments: a case of investigating or imposing preferences? Random Regret-Based Discrete-Choice Modelling: An Application to Healthcare Understanding the impact of economic evidence on clinical decision making: a discrete choice experiment in cardiology. Valuing SF-6D Health States Using a Discrete Choice Experiment A Closer Look at Decision and Analyst Error by Including Nonlinearities in Discrete Choice Models: Implications on Willingness-to-Pay Estimates Derived from Discrete Choice Data in Healthcare Evaluating Health Workers' Potential Resistance to New Interventions: A Role for Discrete Choice Experiments Does attribute framing in discrete choice experiments influence willingness to pay? Results from a discrete choice experiment in screening for colorectal cancer. Using qualitative methods for attribute development for discrete choice experiments: issues and recommendations. Does the Inclusion of a Cost Attribute Result in Different Preferences for the Surgical Treatment of Primary Basal Cell Carcinoma? The Monetary Value of Informal Care: Obtaining Pure Time Valuations Using a Discrete Choice Experiment Public preferences for establishing nephrology facilities in Greenland: estimating willingness-to-pay using a discrete choice experiment Eliciting health state utilities for Dupuytren’s contracture using a discrete choice experiment Prescriber preferences for behavioural economics interventions to improve treatment of acute respiratory infections: a discrete choice experiment Comparison of tools for assessing the methodological quality of primary and secondary studies in health technology assessment reports in Germany How does patients' quality of life guide their preferences regarding aspects of asthma therapy?: a patient-preference study using discrete-choice experiment methodology. An empirical comparison of methods for analyzing correlated data from a discrete choice survey to elicit patient preference for colorectal cancer screening Good practices for real‐world data studies of treatment and/or comparative effectiveness: Recommendations from the joint ISPOR‐ISPE Special Task Force on real‐world evidence in health care decision making Women’s preferences for childbirth experiences in the Republic of Ireland; a mixed methods study [Principles of clinical pharmacology]. General practitioners' preferences for the organisation of primary care: a discrete choice experiment. Improving the reporting of public health intervention research: advancing TREND and CONSORT. Driving up the Quality and Relevance of Research Through the Use of Agreed Core Outcomes Citizen Participation in Patient Prioritization Policy Decisions: An Empirical and Experimental Study on Patients' Characteristics
Investigation of the ' rationality ' of responses to discrete choice experiments ( DCEs ) has been a theme of research in health economics . Responses have been deleted from DCEs where they have been deemed by research ers to ( a ) be ' irrational ' , defined by such studies as failing tests for non-satiation , or ( b ) represent lexicographic preferences . This paper outlines a number of reasons why deleting responses from DCEs may be inappropriate after first review ing the theory underpinning rationality , highlighting that the importance placed on rationality depends on the approach to consumer theory to which one ascribes . The aim of this paper is not to suggest that all preferences elicited via DCEs are rational . Instead , it is to suggest a number of reasons why it may not be the case that all preferences labelled as ' irrational ' are indeed so . Hence , deleting responses may result in the removal of valid preferences ; induce sample selection bias ; and reduce the statistical efficiency and power of the estimated choice models . Further , evidence suggests r and om utility theory may be able to cope with such preferences . Finally , we discuss a number of implication s for the design , implementation and interpretation of DCEs and recommend caution regarding the deletion of preferences from stated preference experiments Background A new modelling approach for analysing data from discrete-choice experiments ( DCEs ) has been recently developed in transport economics based on the notion of regret minimization-driven choice behaviour . This so-called R and om Regret Minimization ( RRM ) approach forms an alternative to the dominant R and om Utility Maximization ( RUM ) approach . The RRM approach is able to model semi-compensatory choice behaviour and compromise effects , while being as parsimonious and formally tractable as the RUM approach . Objectives Our objectives were to introduce the RRM modelling approach to healthcare-related decisions , and to investigate its usefulness in this domain . Methods Using data from DCEs aim ed at determining valuations of attributes of osteoporosis drug treatments and human papillomavirus ( HPV ) vaccinations , we empirically compared RRM models , RUM models and Hybrid RUM – RRM models in terms of goodness of fit , parameter ratios and predicted choice probabilities . Results In terms of model fit , the RRM model did not outperform the RUM model significantly in the case of the osteoporosis DCE data ( p = 0.21 ) , whereas in the case of the HPV DCE data , the Hybrid RUM – RRM model outperformed the RUM model ( p < 0.05 ) . Differences in predicted choice probabilities between RUM models and ( Hybrid RUM- ) RRM models were small . Derived parameter ratios did not differ significantly between model types , but trade-offs between attributes implied by the two models can vary substantially . Conclusion Differences in model fit between RUM , RRM and Hybrid RUM – RRM were found to be small . Although our study did not show significant differences in parameter ratios , the RRM and Hybrid RUM – RRM models did feature considerable differences in terms of the trade-offs implied by these ratios . In combination , our results suggest that RRM and Hybrid RUM – RRM modelling approach hold the potential of offering new and policy-relevant insights for health research ers and policy makers The present study aims to evaluate the impact of  cost-effectiveness information  on clinical decision making using discrete choice experiment ( DCE ) methodology . Data were collected through a self-completed question naire  administered to Italian cardiologists in June 2007 ( n = 129 respondents , 1143 observations ) . The question naire asked clinicians to make choices between paired scenarios , across which three key dimensions were identified and varied : ( 1 ) quality of clinical evidence , ( 2 ) size of health gain ( reduction of relative and absolute risk ) , and ( 3 ) economic impact ( incremental cost-effectiveness ratio ) . A r and om effects probit model was used to estimate clinicians ' preferences for the different dimensions , while the heterogeneity of preferences was tested in a model with interaction terms . Dominance tests were used to assess the consistency of responses . The results indicate that Italian cardiologists regard economic impact ( cost-effectiveness ) as an important factor in their decision making . Economic evidence is valued more highly among clinicians with a higher self-assessed level of knowledge regarding economic evaluation techniques , as well as among younger professionals ( age<45 ) . While relevant study limitations should be acknowledged , our results suggest that DCEs can be used to elicit clinicians ' decision-making criteria and to inform the allocation of re sources for future research in a logical manner . Italian cardiologists appear to take  cost-effectiveness information into account when deciding whether to use new treatments Background . SF-6D utility weights are conventionally produced using a st and ard gamble ( SG ) . SG-derived weights consistently demonstrate a floor effect not observed with other elicitation techniques . Recent advances in discrete choice methods have allowed estimation of utility weights . The objective was to produce Australian utility weights for the SF-6D and to explore the application of discrete choice experiment ( DCE ) methods in this context . We hypothesized that weights derived using this method would reflect the largely monotonic construction of the SF-6D . Methods . We design ed an online DCE and administered it to an Australia-representative online panel ( n = 1017 ) . A range of specifications investigating nonlinear preferences with respect to additional life expectancy were estimated using a r and om-effects probit model . The preferred model was then used to estimate a preference index such that full health and death were valued at 1 and 0 , respectively , to provide an algorithm for Australian cost-utility analyses . Results . Physical functioning , pain , mental health , and vitality were the largest drivers of utility weights . Combining levels to remove illogical orderings did not lead to a poorer model fit . Relative to international SG-derived weights , the range of utility weights was larger with 5 % of health states valued below zero . Conclusion s. DCEs can be used to investigate preferences for health profiles and to estimate utility weights for multi-attribute utility instruments . Australian cost-utility analyses can now use domestic SF-6D weights . The comparability of DCE results to those using other elicitation methods for estimating utility weights for quality -adjusted life-year calculations should be further investigated Background Most research ers in health economics cite r and om utility theory ( RUT ) when analysing discrete choice experiments ( DCEs ) . Under RUT , the error term is associated with the analyst ’s inability to properly capture the true choice processes of the respondent as well as the inconsistency or mistakes arising from the respondent themselves . Under such assumptions , it st and s to reason that analysts should explore more complex nonlinear indirect utility functions , than currently used in healthcare , to strive for better estimates of preferences in healthcare . Objective To test whether complex indirect utility functions decrease error variance for models that either implicitly ( i.e. the multinomial logit ( MNL ) model ) or explicitly ( i.e. entropy multinomial logit ( EMNL ) model ) account for error variance in health(care)-related DCEs ; and to determine the impact of complex indirect utility functions on willingness-to-pay ( WTP ) measures . Methods Using data from DCEs aim ed at healthcare-related decisions , we empirically compared ( 1 ) complex and simple indirect utility specifications in terms of goodness of fit , ( 2 ) their impact on WTP measures , including confidence intervals ( CIs ) based on the Delta method , the Krinsky and Robb-procedure , and Bootstrapping , and ( 3 ) MNL and EMNL model results . Results Complex indirect utility functions had a better model fit than simple specifications ( p < 0.05 ) . WTP estimates were quite similar across alternative specifications . The Delta method produced the most narrow CIs . The EMNL model showed that respondents apply simplifying strategies when answering DCE questions . Conclusion Complex indirect utility functions reduce error arisen from research ers , which can have important implication s for measures in healthcare such as the WTP , whereas EMNL provides insights into the behaviour of respondents when answering DCEs . Underst and ing how respondents answer DCE questions may allow research ers to construct DCEs that minimise scale differences , so that the decision error made across respondents is more homogeneous and therefore taken out as additional noise in the data . Hence , better estimates of preferences in healthcare can be provided Background The currently recommended approach for preventing malaria in pregnancy ( MiP ) , intermittent preventive treatment with sulphadoxine-pyrimethamine ( SP-IPT ) , has been question ed due to the spread of resistance to SP . Whilst trials are underway to test the efficacy of future alternative approaches , it is important to start exploring the feasibility of their implementation . Methods and Findings This study uses a discrete choice experiment ( DCE ) method to assess the potential resistance of health workers to changing strategies for control of MiP. In Ashanti region in Ghana , 133 antenatal clinic health workers were presented with 16 choice sets of two alternative policy options , each consisting of a bundle of six attributes representing certain clinical guidelines for controlling MiP ( type of approach and drug used ) , possible associated maternal and neo-natal outcomes , workload and financial incentives . The data were analysed using a r and om effects logit model . Overall , staff showed a preference for a curative approach with pregnant women tested for malaria parasites and treated only if positive , compared to a preventive approach ( OR 1.6 ; p = 0.001 ) . Increasing the incidence of low birth weight or severe anaemia by 1 % would reduce the odds of preferring an approach by 18 % and 10 % respectively . Midwives were more resistant to potential changes to current guidelines than lower-level cadres . Conclusions In Ashanti Region , resistance to change by antenatal clinic workers from a policy of SP-IPT to IST would generally be low , and it would disappear amongst midwives if health outcomes for the mother and baby were improved by the new strategy . DCEs are a promising approach to identifying factors that will increase the likelihood of effective implementation of new interventions immediately after their efficacy has been proven OBJECTIVE Recent review s of discrete choice methodology identified method ological issues warranting further exploration , including the issue of " framing . " The objective of this study was to conduct a method ological exploration of the effect of attribute framing on marginal rates of substitution ( MRS ) , including willingness to pay ( WTP ) from a discrete choice experiment ( DCE ) , within the context of colorectal cancer screening preferences . METHODS The survey , a fractional factorial design of a two-alternative , unlabeled experiment , was mailed to a sample of 1920 subjects in NSW , Australia . Participants were r and omized to one of four alternative " frames " of information . Attributes included : accuracy of the test for finding cancers , accuracy of the test for finding large polyps , how good the test is at saying you do n't have cancer , cost , dietary and medication restrictions and sample collection . A mixed logit model was used to estimate preferences ; MRS between attributes , including WTP , was calculated . RESULTS A total of 1157 surveys from 1920 ( 60.2 % ) were returned . Accuracy of the test for finding cancer was most likely to influence choice of test , followed by accuracy of the test for finding large polyps . Under some circumstances , framing of the attributes ( e.g. , cancers found vs. cancers missed ) influenced the relative importance of attributes . Attribute framing significantly influenced estimates of WTP , and benefit : harm trade-offs that were calculated from MRS . CONCLUSIONS Attribute framing can influence willingness to pay and benefit : harm trade-offs from DCEs . Appropriate design and analysis methods should be explored to further characterize the influence and extent of framing in discrete choice studies Attribute generation for  discrete choice experiments ( DCEs ) is often poorly reported , and it is unclear whether this element of research is conducted rigorously . This paper explores issues associated with developing attributes for DCEs  and contrasts different qualitative approaches . The paper draws on eight studies , four developed attributes for measures , and four developed attributes  for more ad hoc policy questions . Issues that have become apparent through these studies include the following : the theoretical framework for r and om utility theory and the need for attributes that are neither too close to the latent construct nor too intrinsic to people 's personality ; the need to think about attribute development as a two-stage process involving conceptual development followed by refinement of language to convey the intended meaning ; and the difficulty in resolving tensions inherent in the reductiveness of condensing complex and nuanced qualitative findings into precise terms . The comparison of alternative qualitative approaches suggests that the nature of data collection will depend both on the characteristics of the question ( its sensitivity , for example ) and the availability of existing qualitative information . An iterative , constant comparative approach to analysis is recommended . Finally , the paper provides a series of recommendations for improving the reporting of this element of DCE studies Background : Nowadays , an increasing number of discrete-choice experiments ( DCEs ) incorporate cost as an attribute . However , the inclusion of a cost attribute , particularly within collectively funded healthcare systems , can be challenging because health services or goods are generally not traded in a market situation and individuals are not used to paying for a service or a good at the point of consumption . Objective : To examine whether the inclusion of a cost attribute in a DCE results in different preferences regarding a surgical treatment  for primary basal cell carcinoma ( BCC ) compared with a DCE without a cost attribute . Methods : A r and omized study was performed in which the impact of a cost attribute on the general public ’s preferences for a surgical treatment ( Mohs micrographic surgery [ MMS ] or st and ard excision [ SE ] ) to remove BCC was examined . This was done by comparing the outcomes of two DCEs , one with a cost attribute ( DCE_cost ) and one without ( DCE_nocost ) . Six attributes ( recurrence , re-excision , travel time , surgical time , waiting time for surgical results , costs ) and their levels were selected , based on results of a clinical trial , a cost-effectiveness study , a review and a focus group of patients who had recently received treatment for BCC . Outcomes of both DCEs were compared in terms of theoretical validity , relative importance of the attributes and the rank order of preferences . Results : A total of 615 respondents ( n = 303 for DCE_nocost ; n = 312 for DCE_cost ) were interviewed by telephone . This gave an overall response rate of 38%.Respondents in DCE_nocost preferred a surgical treatment with a lower probability of recurrence , lower surgery time , lower waiting time and no risk for a re-excision . Respondents in DCE_cost showed the same preferences , but also preferred a treatment with less travel time and lower costs . Overall , respondents in both DCEs showed the same preference for a surgical treatment : MMS  was preferred over SE . Conclusion : Results suggest that , in this population , the inclusion of a cost attribute in a DCE leads to the same preference regarding a surgical treatment to remove BCC as a DCE without a cost attribute . However , further research in different setting s is needed to confirm these findings Background Interventions in health care often not only have an effect on patients , but also on their informal caregivers . Caregiving can have a profound impact on the health and wellbeing of carers . Ignoring these spillovers in economic evaluations risks labelling interventions mistakenly as cost-effective , at the expense of informal caregivers . Objective This paper investigates willingness-to-accept ( WTA ) values for an hour of informal care , corrected for positive and negative impacts of informal care , to facilitate the inclusion of informal care hours on the cost side of economic evaluations without double-counting spillover effects . Methods A discrete choice experiment ( DCE ) was conducted among a representative sample of the adult population in the Netherl and s ( n = 552 ) in September 2011 . An experimental design minimizing the D-error was used to construct choice sets with two unlabelled alternatives with the attributes ‘ hours caregiving ’ , ‘ monetary compensation for caregiving ’ and seven impacts of caregiving . To operationalize the r and om utility model , we used a panel mixed multinomial logit ( MMNL ) parameter model . For calculation of WTA , we used both population -level parameters and individual-level parameters . Results The mean WTA for an additional hour of informal care , corrected for positive and negative impacts of informal care , was € 14.57 . The signs of the coefficients were all in the expected directions . Conclusions This study reports a preference-based monetary value for informal care , corrected for other impacts . This valuation facilitates the inclusion of informal care hours on the cost side in economic evaluations without double-counting any spillover effects included on the effects side At present there are no nephrology facilities in Greenl and . Greenl and ic patients with renal failure needing dialysis thus have to travel to Denmark to obtain treatment . For patients in haemodialysis this necessitates a permanent residence in Denmark . Our study was aim ed at examining Greenl and ers ’ preferences for  establishing nephrology facilities in Greenl and at Queen Ingrid ’s Hospital in Nuuk , and to estimate the associated change in welfare . Preferences were elicited using a discrete choice experiment ( DCE ) . A r and om sample of 500 individuals of the general population was sent a postal question naire in which they were asked to consider the trade-offs of establishing nephrology facilities in Greenl and as opposed to the current situation . This involved trading off the benefits of having such facilities in their home country against the costs of the intervention . Besides including a payment attribute described in terms of incremental tax payment , the DCE included two interventions attributes related to ( 1 ) the organisation of labour , and ( 2 ) the physical setting s of the patients . Respondents succeeded in answering the DCE despite cultural and linguistic disparity . We found that all the included attributes had a significant effect on respondents ’ choices , and that respondents ’ answers to the DCE were in keeping with their values as stated in the question naire . DCE data was analyzed using a r and om parameter logit model reparametrized in willingness-to-pay space . The results showed that establishing facilities in Greenl and were preferred to the current treatment in Denmark . The welfare estimate from the DCE , at DKK 18.74 million , exceeds the estimated annual costs of establishing treatment facilities for patients with chronic renal failure . Given the estimated confidence interval this result seems robust . Establishing facilities in Greenl and therefore would appear to be welfare-improving , deriving positive net benefits . Despite the relatively narrow policy focus , we believe that our findings provide some insight into individuals ’ preferences for de central ization of public services and on citizens ’ views of ‘ self-governance ’ that go beyond the case of Greenl and . More generally , this paper illustrates how DCE can be applied successfully to developing countries with culturally , demographically , and geographically distinct features Background and purpose An internet-based discrete choice experiment ( DCE ) was conducted to elicit preferences for a wide range of Dupuytren ’s contracture (DC)-related health states . An algorithm was subsequently developed to convert these preferences into health state utilities that can be used to assess DC ’s impact on quality of life and the value of its treatments . Methods Health state preferences for varying levels of DC h and severity were elicited via an internet survey from a sample of the UK adult population . Severity levels were defined using a combination of contractures ( 0 , 45 , or 90 degrees ) in 8 proximal interphalangeal and metacarpophalangeal joints of the index , middle , ring , and little fingers . Right-h and ed , left-h and ed , and ambidextrous respondents indicated which h and was preferable in each of the 10 r and omly-selected h and -pairings comparing different DC severity levels . For consistency across comparisons , anatomically precise digital h and drawings were used . To anchor preferences onto the traditional 0–1 utility scale used in health economic evaluations , unaffected h and s were assigned a utility of 1.0 whereas the utility for a maximally affected h and ( i.e. , all 8 joints set at 90 degrees of contracture ) was derived by asking respondents to indicate what combination of attributes and levels of the EQ-5D-5L profile most accurately reflects the impact of living with such h and . Conditional logistic models were used to estimate indirect utilities , then rescaled to the anchor points on the EQ-5D-5L . Results Estimated utilities based on the responses of 1,745 qualified respondents were 0.49 , 0.57 , and 0.63 for completely affected dominant h and s , non-dominant h and s , or ambidextrous h and s , respectively . Utility for a dominant h and with 90-degree contracture in t h e metacarpophalangeal joints of the ring and little fingers was estimated to be 0.89 . Separately , reducing the contracture of metacarpophalangeal joint for a little finger from 50 to 12 degrees would improve utility by 0.02 . Interpretation DC is associated with substantial utility decre- ments . The algorithms presented herein provide a robust and flexible framework to assess utility for varying degrees of DC severity Objective To elicit prescribers ' preferences for behavioural economics interventions design ed to reduce inappropriate antibiotic prescribing , and compare these to actual behaviour . Design Discrete choice experiment ( DCE ) . Setting 47 primary care centres in Boston and Los Angeles . Participants 234 primary care providers , with an average 20 years of practice . Main outcomes and measures Results of a behavioural economic intervention trial were compared to prescribers ' stated preferences for the same interventions relative to monetary and time rewards for improved prescribing outcomes . In the r and omised controlled trial ( RCT ) component , the 3 computerised prescription order entry-triggered interventions studied included : Suggested Alternatives ( SA ) , an alert that populated non-antibiotic treatment options if an inappropriate antibiotic was prescribed ; Accountable Justifications ( JA ) , which prompted the prescriber to enter a justification for an inappropriately prescribed antibiotic that would then be documented in the patient 's chart ; and Peer Comparison ( PC ) , an email periodically sent to each prescriber comparing his/her antibiotic prescribing rate with those who had the lowest rates of inappropriate antibiotic prescribing . A DCE study component was administered to determine whether prescribers felt  SA , JA , PC , pay-for-performance or additional clinic time  would most effectively reduce their inappropriate antibiotic prescribing . Willingness-to-pay ( WTP ) was calculated for each intervention . Results In the RCT , PC and JA were found to be the most effective interventions to reduce inappropriate antibiotic prescribing , whereas SA was not significantly different from controls . In the DCE however , regardless of treatment intervention received during the RCT , prescribers overwhelmingly preferred SA , followed by PC , then JA . WTP estimates indicated that each intervention would be significantly cheaper to implement than pay-for-performance incentives of $ 200/month . Conclusions Prescribing behaviour and stated preferences are not concordant , suggesting that relying on stated preferences alone to inform intervention design may eliminate effective interventions . Trial registration number NCT01454947 ; Results Health care policy background Findings from scientific studies form the basis for evidence -based health policy decisions . Scientific background Quality assessment s to evaluate the credibility of study results are an essential part of health technology assessment reports and systematic review s. Quality assessment tools ( QAT ) for assessing the study quality examine to what extent study results are systematic ally distorted by confounding or bias ( internal validity ) . The tools can be divided into checklists , scales and component ratings . Research questions What QAT are available to assess the quality of interventional studies or studies in the field of health economics , how do they differ from each other and what conclusions can be drawn from these results for quality assessment s ? Methods A systematic search of relevant data bases from 1988 onwards is done , supplemented by screening of the references , of the HTA reports of the German Agency for Health Technology Assessment ( DAHTA ) and an internet search . The selection of relevant literature , the data extraction and the quality assessment are carried out by two independent review ers . The substantive elements of the QAT are extracted using a modified criteria list consisting of items and domains specific to r and omized trials , observational studies , diagnostic studies , systematic review s and health economic studies . Based on the number of covered items and domains , more and less comprehensive QAT are distinguished . In order to exchange experiences regarding problems in the practical application of tools , a workshop is hosted . Results A total of eight systematic method ological review s is identified as well as 147 QAT : 15 for systematic review s , 80 for r and omized trials , 30 for observational studies , 17 for diagnostic studies and 22 for health economic studies . The tools vary considerably with regard to the content , the performance and quality of operationalisation . Some tools do not only include the items of internal validity but also the items of quality of reporting and external validity . No tool covers all elements or domains . Design -specific generic tools are presented , which cover most of the content criteria . Discussion The evaluation of QAT by using content criteria is difficult , because there is no scientific consensus on the necessary elements of internal validity , and not all of the generally accepted elements are based on empirical evidence . Comparing QAT with regard to contents neglects the operationalisation of the respective parameters , for which the quality and precision are important for transparency , replicability , the correct assessment and interrater reliability . QAT , which mix items on the quality of reporting and internal validity , should be avoided . Conclusions There are different , design -specific tools available which can be preferred for quality assessment , because of its wider coverage of substantive elements of internal validity . To minimise the subjectivity of the assessment , tools with a detailed and precise operationalisation of the individual elements should be applied . For health economic studies , tools should be developed and complemented with instructions , which define the appropriateness of the criteria . Further research is needed to identify study characteristics that influence the internal validity of studies BACKGROUND AND OBJECTIVE Previous work has suggested that people with poor health-related quality of life ( HR-QOL ) as a result of asthma are willing to pay the most for successful therapy . There is also evidence that preferences are an important influence on adherence to therapy . We report a patient preference study using a discrete-choice experiment ( DCE ) to elicit willingness to pay ( WTP ) of patients with asthma in Spain , the Netherl and s , and the UK . METHODS The DCE survey included different attributes of asthma therapy ( days with symptoms , days needing reliever medication , asthma attacks [ none , attack that does not require doctor/emergency room { ER } visit , attack that requires doctor/ER visit ] , risk of adverse effects , number of preventer inhalers , and monthly out-of-pocket costs ) . Participants indicated which attribute combinations they preferred . The question naire survey included the  mini Asthma Quality of Life Question naire ( mAQLQ ) .  The validity of the choice experiment has been supported by two pilot studies conducted in the UK . Preferences and WTP were estimated using a r and om effects probit model . Symptom days and asthma attack attributes were segmented by mAQLQ score . RESULTS Demographic and clinical data were compared between the three country sample s ( UK , n = 124 ; Spain , n = 86 ; the Netherl and s , n = 269 ) . All study attributes were independently significant predictors of choice . People were willing to pay € 35 per month to avoid a day with symptoms , and € 109 per month ( year 2005 values ) to avoid experiencing asthma attacks that required emergency visits to their doctor or hospital . People with the worst HR-QOL were willing to pay the least to avoid days with symptoms and asthma attacks that required visits to their doctor/ER . This was not an income-related effect . CONCLUSION Patients who reported higher HR-QOL  were willing to pay more to avoid days with symptoms and asthma attacks that required visits to their doctor/ER . Hypotheses were explored to explain this effect . It is possible that people with the least impairment of HR-QOL place the greatest value on avoiding the effects of asthma and so are most willing to alter their behavior . People with the worst HR-QOL may be exhibiting a response shift type of effect whereby their internal values are shifted down by the burden of their disease . These findings may help to illuminate why there are differences in asthma treatment adherence Background A discrete choice experiment ( DCE ) is a preference survey which asks participants to make a choice among product portfolios comparing the key product characteristics by performing several choice tasks . Analyzing DCE data needs to account for within-participant correlation because choices from the same participant are likely to be similar . In this study , we empirically compared some commonly-used statistical methods for analyzing DCE data while accounting for within-participant correlation based on a survey of patient preference for colorectal cancer ( CRC ) screening tests conducted in Hamilton , Ontario , Canada in 2002 . Methods A two-stage DCE design was used to investigate the impact of six attributes on participants ' preferences for CRC screening test  and willingness to undertake the test . We compared six models for clustered binary outcomes ( logistic and probit regressions using cluster-robust st and ard error ( SE ) , r and om-effects and generalized estimating equation approaches ) and three models for clustered nominal outcomes ( multinomial logistic and probit regressions with cluster-robust SE and r and om-effects multinomial logistic model ) . We also fitted a bivariate probit model with cluster-robust SE treating the choices from two stages as two correlated binary outcomes . The rank of relative importance between attributes and the estimates of βcoefficient within attributes were used to assess the model robustness . Results In total 468 participants with each completing 10 choices were analyzed . Similar results were reported for the rank of relative importance and βcoefficients across models for stage-one data on evaluating participants ' preferences for the test . The six attributes ranked from high to low as follows : cost , specificity , process , sensitivity , preparation and pain . However , the results differed across models for stage-two data on evaluating participants ' willingness to undertake the tests . Little within-patient correlation ( ICC ≈ 0 ) was found in stage-one data , but substantial within-patient correlation existed ( ICC = 0.659 ) in stage-two data . Conclusions When small clustering effect presented in DCE data , results remained robust across statistical models . However , results varied when larger clustering effect presented . Therefore , it is important to assess the robustness of the estimates via sensitivity analysis using different models for analyzing clustered data from DCE studies Abstract Purpose Real‐world evidence ( RWE ) includes data from retrospective or prospect i ve observational studies and observational registries and provides insights beyond those addressed by r and omized controlled trials . RWE studies aim to improve health care decision making . Methods The International Society for Pharmacoeconomics and Outcomes Research ( ISPOR ) and the International Society for Pharmacoepidemiology ( ISPE ) created a task force to make recommendations regarding good procedural practice s that would enhance decision makers ' confidence in evidence derived from RWD studies . Peer review by ISPOR/ISPE members and task force participants provided a consensus‐building iterative process for the topics and framing of recommendations . Results The ISPOR/ISPE Task Force recommendations cover seven topics such as study registration , replicability , and stakeholder involvement in RWE studies . These recommendations , in concert with earlier recommendations about study methodology , provide a trustworthy foundation for the exp and ed use of RWE in health care decision making . Conclusion The focus of these recommendations is good procedural practice s for studies that test a specific hypothesis in a specific population . We recognize that some of the recommendations in this report may not be widely adopted without appropriate incentives from decision makers , journal editors , and other key stakeholders Background How women experience childbirth is acknowledged as critical to the postnatal wellbeing of mother and baby . However there is a knowledge deficit in identifying the important elements of these experiences in order to enhance care . This study elicits women ’s preferences for the most important elements of their childbirth experiences . Methods A mixed methods design was used . An initial qualitative phase ( reported previously ) was followed by a second quantitative one using a discrete choice experiment ( DCE ) , which is reported on here . Participants who had experienced labour , were over 18 and had a healthy baby were recruited from four r and omly selected and one pilot hospital in the Republic of Irel and . Data were collected by means of a DCE survey instrument . Questions were piloted , refined , and then arranged in eight pair-wise scenarios . Women identified their preferences by choosing one scenario over another . Nine hundred and five women were sent the DCE three months after childbirth , with a response rate of 59.3 % ( N = 531 ) . Results Women clearly identified priorities for their childbirth experiences as : the availability of pain relief , partnership with the midwife , and individualised care being the most important attributes . In the context of other choices , women rated decision-making , presence of a consultant , and interventions as less important elements . Comments from open questions provided context ual information about their choices . Conclusions Most women did not want to be typified as wanting the dichotomy of ‘ all natural ’ or ‘ all technology ’ births but wanted ‘ the best of both worlds ’ . The results suggest that availability of pain relief was the most important element of women ’s childbirth experiences , and superseded all other elements including partnership with the midwife which was the second most important attribute . The preferences identified might reflect the busy medicalised hospital environments , in which the vast majority of women had given birth , and may differ in setting s such as midwifery led care or home births 626 pages , 2012 , Academic Press , 2012 , Arthur J. Atkinson ( Jr. ) , Shiew-Mei Huang , Principles of Clinical Pharmacology , 0123854717 , 9780123854711 , Principles of Clinical Pharmacology is a successful survey covering the pharmacologic principles underlying the individualization of patient therapy and contemporary drug development . This essential reference continues to focus on the basics of clinical pharmacology for the development , evaluation , and clinical use of pharmaceutical products while also addressing the most recent advances in the field . Written by leading experts in academia , industry , clinical and regulatory setting s , the third edition has been thoroughly up date d to provide readers with an ideal reference covering the wide range of important topics impacting clinical pharmacology as the discipline plays an increasingly significant role in drug development and regulatory science . The Third Edition has been endorsed by the American Society for Clinical Pharmacology and Therapeutics * Includes new chapters on imaging and the pharmacogenetic basis of adverse drug reactions . * Offers an exp and ed regulatory section that addresses US and international issues and guidelines . * Provides extended coverage of earlier chapters on transporters , pharmacogenetics and biomarkers and also illustrates the impact of gender on drug response . * Presents a broadened discussion of clinical trials from Phase 1 to incorporate Phases II and III . file download OBJECTIVES To examine GPs ' preferences for organisational characteristics in general practice with focus on aspects that can potentially mitigate problems with GP shortages . METHODS A simple r and om sample of 1823 GPs ( corresponding to half of all GPs in Denmark ) was drawn at the beginning of 2010 , and a response rate of 68 % was obtained . A discrete choice experiment ( DCE ) is applied , and attributes included are :  practice type ( solo/shared ) , number of GPs in general practice , collaboration with other practice s ( yes/no ) , change in weekly working hours ( administrative versus patient related ) and change in yearly surplus . Multinomial logit analyses ( with and without interaction variables ) are used , and marginal rates of substitution are calculated . RESULTS GPs working in solo practice s have different preferences for the organisational attributes compared to GPs in shared practice s. The compensation needed for GPs to re-organise from solo to shared practice is associated with the size of the practice . GP characteristics such as age , working hours and surplus affect their willingness to undergo organisational changes . CONCLUSIONS Our results are of relevance to decision makers in design ing policies aim ed at influencing GPs ' organisation in order to overcome problems related to shortages BACKGROUND Evidence -based public health decision-making depends on high quality and transparent accounts of what interventions are effective , for whom , how and at what cost . Improving the quality of reporting of r and omized and non-r and omized study design s through the CONSORT and TREND statements has had a marked impact on the quality of study design s. However , public health users of systematic review s have been concerned with the paucity of synthesized information on context , development and rationale , implementation processes and sustainability factors . METHODS This paper examines the existing reporting frameworks for research against information sought by users of systematic review s of public health interventions and suggests additional items that should be considered in future recommendations on the reporting of public health interventions . RESULTS Intervention model , theoretical and ethical considerations , study design choice , integrity of intervention/process evaluation , context , differential effects and inequalities and sustainability are often overlooked in reports of public health interventions . CONCLUSION Population health policy makers need synthesized , detailed and high quality a priori accounts of effective interventions in order to make better progress in tackling population morbidities and inequalities . Adding simple criteria to reporting st and ards will significantly improve the quality and usefulness of published evidence and increase its impact on public health program planning There is a growing recognition that insufficient attention has been paid to the selection of the outcomes to measure in clinical trials and clinical audit . Outcomes need to be relevant to patients , clinicians , purchasers and policy-makers if the findings of research are to influence practice and future research . In addition , st and ardization of outcomes is needed to combine data from different studies to allow evidence synthesis and to compare data sets . Inconsistent choice of outcome measures means that many meta-analyses are unable to include data from all the relevant studies . For example , the five most accessed Cochrane review s in 2009 , together with the top cited review in that year , all described inconsistencies in the outcomes reported in eligible trials . A call for the st and ardization of outcomes is a regular conclusion of systematic review s. Furthermore , outcome reporting bias , defined as the bias arising from selecting outcomes for publication based on the results , affects many r and omized trials and ‘ is an under-recognized problem that affects the conclusions in a substantial proportion of Cochrane review s ’ . That bias is likely to affect systematic review s more widely as well as affecting individual studies when considered on their own . Similar problems occur with clinical audit , highlighting the importance of establishing national audits that use and report the same outcomes for all participants . All these issues could be addressed with the development and application of agreed st and ardized sets of outcomes that have been termed ‘ core outcome sets ’ . These should be measured and reported , as a minimum , in all relevant clinical trials and national clinical audits for a specific condition . Adopting a core outcome set does not imply that a particular study , review or audit should be restricted to only those outcomes . Rather , the expectation is that , as a minimum , core outcomes will always be collected and reported to allow the results of trials to be compared , contrasted and combined as appropriate . The adoption of core outcomes would have implication s across all areas of research in health and health care , reduce heterogeneity between trials , and lead to research that is more likely to have measured relevant outcomes . Importantly , they would enhance the value of evidence synthesis by reducing the risk of outcome reporting bias and ensuring that all trials contribute usable information . In addition , they will increase the efficiency and value of research . An important rationale for core outcome sets is that outcomes currently reported for trials do not consistently reflect endpoints that are meaningful for patients . Examples exist where trials failed to include all outcomes important to patients and where involvement of patients has identified an outcome that might not have been considered by practitioners on their own . Despite increasing recognition of the importance of incorporating patients ’ opinions , their involvement has been limited . Recent regulatory guidance in the USA requires documented evidence of patient input during the development of instruments to measure  patient reported outcomes ( PROs ) . However , measurement of PROs in clinical trials is hampered by the multiplicity and heterogeneity of tools currently available . Many generic , disease and domain-specific instruments have been developed and vali date d , each containing multiple scales and items . As a result , synthesis of PRO data from trials is difficult and review s aim ing to summarize treatment effect according to PROs may fail . There is synergy between the development of core outcome sets for trials and work to select up to seven outcomes that are important to patients for inclusion in Summary of Findings tables in systematic review s. Developed by the GRADE group ( http://www . grade workinggroup.org ) , Cochrane review s have featured such tables since 2008 , and they play a key role in presenting research in guidelines , such as those produced by the World Health Organization ( WHO ) . The development of core outcome sets needs to be accelerated and undertaken in ways that maximize efficiency . The COMET ( Core Outcome Measures in Effectiveness Trials , http://www.comet-initiative.org ) Initiative in the UK brings together research ers interested in the development and application of core outcome sets . These include key participants in a collaboration of research ers in rheumatology who have done the most notable work to date in this area . The COMET Initiative was launched in January 2010 , with a second meeting in July 2011 . Attendees included trialists , systematic review ers , patients , clinicians , journal editors , research funders , policy-makers , people responsible for trials registries and regulators . Data on individual studies , both published and ongoing , are being included in a free , publically available internet-based re source . This will be up date d periodically , to minimize the risk of duplication . Seventy-eight published or ongoing studies have already been entered into the repository . In addition , published review s of outcomes used in clinical trials or studies examining patients ’ views , will be entered Health systems worldwide are grappling with the need to control costs to maintain system viability . With the combination of worsening economic conditions , an aging population and reductions in tax revenues , the pressures to make structural changes are expected to continue growing . Common cost control mechanisms , e.g. curtailment of patient access and treatment prioritization , are likely to be adversely viewed by citizens . It seems therefore wise to include them in the decision making processes that lead up to policy changes . In the context of a multilevel iterative mixed- method design a quantitative survey representative of the German population ( N = 2031 ) was conducted to probe the acceptance of priority setting in medicine and to explore the practicability of direct public involvement . Here we focus on preferences for patients ' characteristics ( medical aspects , lifestyle and socio-economic status ) as possible criteria for prioritizing medical services . A question naire with closed response options was fielded to gain insight into attitudes toward broad prioritization criteria of patient groups . Furthermore , a discrete choice experiment was used as a rigorous approach to investigate citizens ' preferences toward specific criteria level in context of other criteria . Both the question naire and the discrete choice experiment were performed with the same sample . The citizens ' own health and social situation are included as explanatory variables . Data were evaluated using corresponding analysis , contingency analysis , logistic regression and a multinomial exploded logit model . The results show that some medical criteria are highly accepted for prioritizing patients whereas socio-economic criteria are rejected
We found a continuing trend towards conducting DCEs across a broader range of countries .
However , the trend towards including fewer attributes was reversed , whilst the trend towards interview-based DCEs reversed because of increased computer administration .
The trend towards using more flexible econometric models , including mixed logit and latent class , has also continued .
Reporting of monetary values has fallen compared with earlier periods , but the proportion of studies estimating trade-offs between health outcomes and experience factors , or valuing outcomes in terms of utility scores , has increased , although use of odds ratios and probabilities has declined .
The reassuring trend towards the use of more flexible and appropriate DCE design s and econometric methods has been reinforced by the increased use of qualitative methods to inform DCE processes and results .
However , qualitative research methods are being used less often to inform attribute selection , which may make DCEs more susceptible to omitted variable bias if the decision framework is not known prior to the research project .
Background Discrete choice experiments ( DCEs ) are increasingly used in health economics to address a wide range of health policy-related concerns .
Objective Broadly adopting the methodology of an earlier systematic review of health-related DCEs , which covered the period 2001–2008 , we report whether earlier trends continued during 2009–2012 .