Incidence and preventability of adverse drug events in nursing homes

PURPOSE: Adverse drug events, especially those that may have been preventab le, are among the most serious concerns about medication use in nursing hom es. We studied the incidence and preventability of adverse drug events and potential adverse drug events in nursing homes. METHODS: We performed a cohort study of all long-term care residents of 18 community-based nursing homes in Massachusetts during a 12-month observatio n period. Potential drug-related incidents were detected by stimulated self -report by nursing home staff and by periodic review of the records of nurs ing home residents by trained nurse and pharmacist investigators. Each inci dent was classified by 2 independent physician-reviewers, using a structure d implicit review process, by whether or not it constituted an adverse drug event or potential adverse drug event (those that may have caused harm, bu t did not because of chance or because they were detected), by the severity of the event (significant, serious, life-threatening, or fatal), and by wh ether it was preventable. Examples of significant events included nonurtica rial rashes, falls without associated fracture, hemorrhage not requiring tr ansfusion or hospitalization, and oversedation; examples of serious events included urticaria, falls with fracture, hemorrhage requiring transfusion o r hospitalization, and delirium. RESULTS: During 28,839 nursing home resident-months of observation in the 1 8 participating nursing homes, 546 adverse drug events (1.89 per 100 reside nt-months) and 188 potential adverse drug events (0.65 per 100 resident-mon ths) were identified. Of the adverse drug events, 1 was fatal, 31 (6%) were life-threatening, 206 (38%) were serious, and 308 (56%) were significant. Overall, 51% of the adverse drug events were judged to be preventable, incl uding 171 (72%) of the 238 fatal, life-threatening, or serious events and 1 05 (34%) of the 308 significant events (P < 0.001). Errors resulting in pre ventable adverse drug events occurred most often at the stages of ordering and monitoring; errors in transcription, dispensing, and administration wer e less commonly identified. Psychoactive medications (antipsychotics, antid epressants, and sedatives/hypnotics) and anticoagulants were the most commo n medications associated with preventable adverse drug events. Neuropsychia tric events were the most common types of preventable adverse drug events. CONCLUSIONS: Adverse drug events are common and often preventable in nursin g homes. More serious adverse drug events are more likely to be preventable . Prevention strategies should target the ordering and monitoring stages of pharmaceutical care. Am J Med. 2000;109:87-94. (C) 2000 by Excerpta Medica , Inc.