The study protocol (available at NEJM.org) was
approved by the institutional review board of each
participating institution. The parents of children
and adolescents who participated in the study provided
written informed consent, and the children
and adolescents provided their assent. Safety and
risk management were monitored by the independent
data and safety monitoring board. Serious
adverse events were reported as they occurred. In
addition to the standard monitoring of serious
adverse events, three study-specific serious adverse
events were tracked: severe hypoglycemia, diabetic
ketoacidosis, and lactic acidosis.