“…The methods employed in the empirical studies were classified into three categories: i) retrospective studies of pointprevalence or period-prevalence of PEs carried out using the patient's clinical records, databases on adverse reactions or data on medication intoxication, which, in some cases, included checking or complementing the information through patient interviews, studies involving semi-structured or structured interviews or surveys with samples of adult patients ( Table 2) [25,28,35,[37][38][39][40]42,[45][46][47][48][49][52][53][54][55]60,65,69,71,77]; and with samples of parents' or caregivers' children ( Table 3) [22,23,27,30,32,33,36,43,63,66,68,75]; ii) studies based on adverse reactions to drugs registered in the databases of Poison Centers (Table 4) [58,64,80]; and iii) studies on intervention for reducing the number of errors (Table 5) [29,31,34,44,…”