ImportanceAdenotonsillectomy, performed for approximately 500 000 children annually in the US alone, is the first line of treatment of pediatric obstructive sleep apnea (OSA). The Childhood Adenotonsillectomy Trial (CHAT), the first randomized clinical trial to test the efficacy of adenotonsillectomy, compared the management of pediatric nonsevere OSA by early adenotonsillectomy (eAT) vs watchful waiting with supportive care. Since the publication of the primary article in 2013, the CHAT study data set were made available via the National Sleep Research Resource, which allowed researchers to address a range of additional clinical questions relevant to the care of children with OSA. This review focuses on secondary analyses associated with the CHAT data set as grouped by the outcome of interest.ObservationsThe results of most secondary analyses suggest that children who underwent eAT experienced the greatest improvements in symptom burden, sleepiness, parent-reported behavior, and quality of life. Changes in other domains, such as cognition, cardiovascular physiology, and metabolic indicators, were modest and selective. The associations between most treatment outcomes and polysomnographic parameters were weak. Symptoms were poor predictors of OSA severity. The results from these secondary analyses benefitted from the rigor of multicenter design and centralized polysomnography interpretation in CHAT. However, the exclusion of younger preschool-aged children and children with primary snoring limited the generalizability of findings. In addition, because caregivers were not masked, some of the parent-reported outcomes may have been inflated.Conclusions and RelevanceThe results of this narrative review suggest that CHAT provides a model for future OSA-related studies in children for design, conduct, and subsequent reuse of the study data set, and its findings have advanced our understanding of the pathophysiology and management of pediatric nonsevere OSA. Directions for future research include whether the findings from this landmark study are generalizable to younger children and children with primary snoring and severe OSA. Similar studies may help address practice variability associated with pediatric OSA and help identify children who are most likely to benefit from undergoing eAT.