The prevention and treatment of missing data in clinical trials.

Missing data have seriously compromised inferences from clinical trials, yet the topic has received little attention in the clinical-trial community.1 Existing regulatory guidances2-4 on the design, conduct, and analysis of clinical trials have little specific advice on how to address the problem of missing data. A recent National Research Council (NRC) report5 on the topic seeks to address this gap, and this article summarizes some of the main findings and recommendations of that report. The authors of this article served on the panel that prepared the report.