On the construction of bounds in prospective studies with missing ordinal outcomes: application to the good behavior game trial

This article is concerned with drawing inference about aspects of the population distribution of ordinal outcome data measured on a cohort of individuals on two occasions, where some subjects are missing their second measurement. We present two complementary approaches for constructing bounds under assumptions on the missing data mechanism considered plausible by scientific experts. We develop our methodology within the context of a randomized trial of the "Good Behavior Game," an intervention designed to reduce aggressive misbehavior among children.