Based on our review, recent studies demonstrate that the burden of adverse drug reactions (ADRs), in both in- and outpatient settings, is substantial.

Data regarding the burden of ADRs in the outpatient setting, especially those ADRs that do not result in healthcare use, are largely lacking as we were only able to identify a handful of studies.

Despite the large number of studies we identified, several countries had no recent studies available. Therefore, studies in all European countries, as well as studies on ADR occurrence in the outpatient setting, are needed.