Patient Risk Factors for Adverse Drug Events in Hospitalized Patients

Abstract

ADVERSE DRUG events (ADEs) are an important and costly problem.^1-4 The Medical Practice Study, which examined patients hospitalized in New York State in 1984, found that almost 1% of patients experienced an injury due to drugs that resulted in disability or prolongation of their hospital stay.^5,6 Other studies,^7-17 most of which used the adverse drug reaction as the outcome, have also shown that injuries due to drugs are common among hospitalized patients. The term "adverse drug reaction," as defined by the World Health Organization,¹⁸ excludes events associated with errors, while the term "ADE" includes preventable and nonpreventable events.¹⁹ In earlier reports^20,21 from the ADE Prevention Study, we found an average of 6.5 ADEs per 100 admissions, of which 28% were preventable.