When evaluating the accuracy of a diagnostic medical device, either compare to the reference standard or to a predicate device that is already on the market, missing data, including missing reference standard, and/or missing test result (either from the single test or from any of the two tests), are commonly encountered. Reporting diagnostic results using only completers can introduce bias to the diagnostic accuracy estimates. And more sophisticated statistical approaches are needed. Discussions on experiences and possible solutions among industrial, academic and regulatory researchers are planned in this roundtable session.