Sample Size and Utility-Difference Precision in Discrete-Choice Experiments: A Meta-Simulation Approach

• A meta-simulation strategy analyzes what affects utility-difference precision. • Meta-data are obtained from 34 individual DCE patient-preference data sets. • Utility-difference precision is regressed on sample size and study characteristics. • Study-design features affect precision more than experimental-design efficiency. • An empirical sample-size power equation is derived for DCE health studies.