There is a lack of homogeneity in the terminology used in the context of patient safety related to medication. The aim of this review was to identify the terms and definitions used in patient safety related to medication within the scientific literature.Original and review articles that were indexed between 1998 and 2008 in MEDLINE and EMBASE and contained terms used in patient safety related to medication were included. Terms and definitions were extracted and categorised according to whether its definition referred to the process of medication use, or to the clinical outcome of medication use, or both.Of 2564 articles, 147 were included. Sixty terms used in patient safety related to medication with 189 different definitions were identified. Among terms that referred only to the process of medication use (n = 23), medication error provided the greatest number of definitions (n = 29). Among terms that referred only to the clinical outcome of medication use (n = 31), adverse drug event provided the greatest number of definitions (n = 15). Finally, among terms that referred both to the process of use and to the clinical outcome of medication use (n = 13), drug-related problem provided the greatest number of definitions (n = 7).A multitude of terms and definitions are used in patient safety related to medication. This heterogeneity makes it difficult to compare the results among studies and to appreciate the true magnitude of the problem. Classifying and unifying the terminology is necessary to advance in patient safety strategies.
