SYSTEMS-ANALYSIS OF ADVERSE DRUG EVENTS

Objective.-To identify and evaluate the systems failures that underlie errors causing adverse drug events (ADEs) and potential ADEs. Design. -Systems analysis of events from a prospective cohort study. Participa nts.-All admissions to 11 medical and surgical units in two tertiary c are hospitals over a 6-month period. Main Outcome Measures.-Errors, pr oximal causes, and systems failures. Methods.-Errors were detected by interviews of those involved. Errors were classified according to prox imal cause and underlying systems failure by multidisciplinary teams o f physicians, nurses, pharmacists, and systems analysts. Results.-Duri ng this period, 334 errors were detected as the causes of 264 preventa ble ADEs and potential ADEs. Sixteen major systems failures were ident ified as the underlying causes of the errors. The most common systems failure was in the dissemination of drug knowledge, particularly to ph ysicians, accounting for 29% of the 334 errors. Inadequate availabilit y of patient information, such as the results of laboratory tests, was associated with 18% of errors. Seven systems failures accounted for 7 8% of the errors; all could be improved by better information systems. Conclusions.-Hospital personnel willingly participated in the detecti on and investigation of drug use errors and were able to identify unde rlying systems failures. The most common defects were in systems to di sseminate knowledge about drugs and to make drug and patient informati on readily accessible at the time it is needed. Systems changes to imp rove dissemination and display of drug and patient data should make er rors in the use of drugs less likely.