Commentary

Any discussion of patient safety usually begins with citations from the report of the Institute of Medicine (IOM) ''To Err is Human'' 1 released in 1999.However, there were core articles that preceded To Err is Human which were used to form the basis of this landmark study.The paper by Classen et al 2 published in JAMA in 1991 is one of those articles.Classen and colleagues described how adverse drug events could be identified in an integrated hospital information system using a computer program to detect a variety of indicators of harm associated with adverse drug events.