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 .
A comparison of two experimental design approaches in applying conjoint analysis in patient-centered outcomes research: a randomized trial.
BACKGROUND While the application of conjoint analysis and discrete-choice experiments in health are now widely accepted , a healthy debate exists around competing approaches to experimental design . There remains , however , a paucity of experimental evidence comparing competing design approaches and their impact on the application of these methods in patient-centered outcomes research . OBJECTIVES Our objectives were to directly compare the choice-model parameters and predictions of an orthogonal and a D-efficient experimental design using a r and omized trial ( i.e. , an experiment on experiments ) within an application of conjoint analysis study ing patient-centered outcomes among out patients diagnosed with schizophrenia in Germany . METHODS Out patients diagnosed with schizophrenia were surveyed and r and omized to receive choice tasks developed using either an orthogonal or a D-efficient experimental design . The choice tasks elicited judgments from the respondents as to which of two patient profiles ( varying across seven outcomes and process attributes ) was preferable from their own perspective . The results from the two survey design s were analyzed using the multinomial logit model , and the result ing parameter estimates and their robust st and ard errors were compared across the two arms of the study ( i.e. , the orthogonal and D-efficient design s ) . The predictive performances of the two result ing models were also compared by computing their percentage of survey responses classified correctly , and the potential for variation in scale between the two design s of the experiments was tested statistically and explored graphically . RESULTS The results of the two models were statistically identical . No difference was found using an overall chi-squared test of e quality for the seven parameters ( p = 0.69 ) or via uncorrected pairwise comparisons of the parameter estimates ( p-values ranged from 0.30 to 0.98 ) . The D-efficient design result ed in directionally smaller st and ard errors for six of the seven parameters , of which only two were statistically significant , and no differences were found in the observed D-efficiencies of their st and ard errors ( p = 0.62 ) . The D-efficient design result ed in poorer predictive performance , but this was not significant ( p = 0.73 ) ; there was some evidence that the parameters of the D-efficient design were biased marginally towards the null . While no statistical difference in scale was detected between the two design s ( p = 0.74 ) , the D-efficient design had a higher relative scale ( 1.06 ) . This could be observed when the parameters were explored graphically , as the D-efficient parameters were lower . CONCLUSIONS Our results indicate that orthogonal and D-efficient experimental design s have produced results that are statistically equivalent . This said , we have identified several qualitative findings that speak to the potential differences in these results that may have been statistically identified in a larger sample . While more comparative studies focused on the statistical efficiency of competing design strategies are needed , a more pressing research problem is to document the impact the experimental design has on respondent efficiency
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 .