Prospective studies that reported sufficient data to calculate incidence of adverse drug reactions in unselected populations of children and adolescents were eligible for inclusion in the review. Studies were excluded if they assessed adverse drug events defined as "any injury resulting from medical interventions related to a drug", including complications that resulted from medication errors and adverse drug reactions where no error occurred.
Most included studies focused on hospitalised children and adverse drug reactions that resulted in hospital admissions; others included adverse drug reactions during out-patient treatments. Incidence of adverse drug reactions ranged from 1.5% to 19.9% among hospitalised children. Age of children ranged from 0 to 18 years. The most commonly affected systems were the gastrointestinal system and skin. The most common therapeutic classes of interventions were central nervous system drugs and anti-infective agents. A quarter of the studies were conducted in France and a quarter in Germany. Study duration ranged from 0.25 to 11 months; most studies were carried out over a five- or six-month period.
The authors stated neither how papers were selected for review nor how many reviewers performed the selection.