Missing data in clinical trials can have a major effect on the validity of the inferences that can be drawn from the trial this article reviews methods for preventing missing data and failing tha. The prevention and treatment of missing data in clinical trials the prevention and treatment of missing data in clinical trials the prevention and treatment of missing data in clinical trials n engl j med 2012 oct 4367141355 60 doi 101056 nejmsr1203730 authors roderick j little 1 ralph dagostino michael l cohen kay dickersin scott s emerson john t farrar constantine . The prevention and treatment of missing data in clinical trials concludes that a more principled approach to design and analysis in the presence of missing data is both needed and possible such an approach needs to focus on two critical elements 1 careful design and conduct to limit the amount and impact of missing data and 2 analysis that makes full use of information on all randomized participants and is based on careful attention to the assumptions about the nature of the missing . N engl j med 2012 oct 4 36714 1355 1360 doi 101056 nejmsr1203730 pmcid pmc3771340