Trends in Off-Label Drug Use in Ambulatory Settings: 2006-2015.

BACKGROUND: Off-label drug use in children is common and potentially harmful. In most previous off-label use research, authors studied hospitalized children, specific drug classes, or non-US settings. We characterized frequencies, trends, and reasons for off-label systemic drug orders for children in ambulatory US settings. METHODS: Using nationally representative surveys of office-based physicians (National Ambulatory Medical Care Surveys, 2006-2015), we studied off-label orders of systemic drugs for children age <18 based on US Food and Drug Administration-approved labeling for age, weight, and indication. We characterized the top classes and diagnoses with off-label orders and analyzed factors and trends of off-label orders using logistic regression. RESULTS: Physicians ordered ≥1 off-label systemic drug at 18.5% (95% confidence interval: 17.7%-19.3%) of visits, usually (74.6%) because of unapproved conditions. Off-label ordering was most common proportionally in neonates (83%) and in absolute terms among adolescents (322 orders out of 1000 visits). Off-label ordering was associated with female sex, subspecialists, polypharmacy, and chronic conditions. Rates and reasons for off-label orders varied considerably by age. Relative and absolute rates of off-label orders rose over time. Among common classes, off-label orders for antihistamines and several psychotropics increased over time, whereas off-label orders for several classes of antibiotics were stable or declined. CONCLUSIONS: US office-based physicians have ordered systemic drugs off label for children at increasing rates, most often for unapproved conditions, despite recent efforts to increase evidence and drug approvals for children. These findings can help inform education, research, and policies around effective, safe use of medications in children.