In this secondary systematic review of single-case and controlled group design intervention studies conducted with transition-age autistic youth, we examined features of 48 studies with 273 participants that measured at least one “problem behavior” outcome (Prospero registration number: 231764). We searched 11 databases for relevant studies, and the final search date was November 2022. Our primary aims were to determine how problem behaviors were defined and selected for reduction, how functions were determined, and the interventions used to address them. Studies were coded and codes were tabulated and converted to percentages to answer each research question. Thirty-eight percent of studies defined problem behavior, and 88% of studies implemented behavioral strategies to reduce problem behaviors. Behaviors with low potential for harm constituted the majority of the 67 outcome variables (61%), while behaviors with high potential for harm were a minority (39%). The most common intervention target was stereotypic behavior. Fewer than half of studies: reported procedures for selecting behaviors, reported procedures to determine behavior function, or ascribed functions to behaviors. We were unable to report on some demographic features of participants (e.g. race/ethnicity) because they were rarely reported in primary studies. We conclude that problem behavior is poorly conceptualized in this research. Lay abstract In a previous study, we looked at research done on strategies to support autistic people who were between 14 and 22 years old. For this study, we looked at all of the studies in our previous study that tried to decrease or stop autistic people from doing certain things—many researchers call these things “problem behavior.” There were 48 studies that tried to reduce problem behavior, and most of them used strategies like prompting and reinforcement to try get autistic people to change their behavior. We found many things wrong with these studies. Most of them did not define the group of behaviors they were trying to stop autistic people from doing. None of the studies looked at whether any side effects happened when they tried the strategy they were studying. Also, most of the studies tried to stop autistic people from doing behaviors that probably were not harmful, like stereotypic behavior. Most of the studies did not say how they decided that the behaviors they tried to stop were a problem for the autistic people in the study, and most studies did not try to figure out why the autistic people in the study did the behaviors the researchers were trying to stop them from doing.
