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Adverse drug events occur frequently in long-term care facilities, and nearly half of them are preventable

A new study of two large, long-term care facilities in Canada and Connecticut identified nearly 10 adverse drug events (ADEs) per 100 resident-months. Over four ADEs per 100 resident-months (42 percent) were judged preventable. About 61 percent of the 225 serious, life-threatening, or fatal ADEs were deemed preventable compared with 34 percent of the 590 less serious ADEs. Over 70 percent of ADEs resulted in symptoms lasting more than 1 day. Six events resulted in permanent disability or death. Neuropsychiatric events (for example, oversedation, confusion, hallucinations, delirium) were the most common type of preventable event and second most common type of non-preventable event, according to the study which was supported by the Agency for Healthcare Research and Quality (HS10481).

The most frequently identified types of preventable ADEs included gastrointestinal (abdominal pain, diarrhea, constipation, impaction), hemorrhagic (bleeding events), renal/electrolytes (for example, dehydration and renal failure), and metabolic/endocrine (hypoglycemic events, thyroid abnormalities) events. Warfarin, atypical antipsychotics, loop diuretics, intermediate-acting benzodiazepines, opioids, and angiotensin-converting enzyme inhibitors were the medications most commonly involved in ADEs.

After adjusting for multiple factors, residents taking drugs in several drug categories were at increased risk of a preventable ADE (odds ratio, OR of 3.4 for those taking antipsychotics, 2.8 for anticoagulants, 2.2 for diuretics, and 2.0 for antiepileptics). These findings reinforce the need to focus on the ordering and monitoring of drug therapies to prevent ADEs in long-term care patients, notes lead researcher Jerry H. Gurwitz, M.D., of the University of Massachusetts Medical School. Study findings are based on analyses of ADEs over an 8-month period in one facility and a 9-month period in another facility during 2000 and 2001.

More details are in "The incidence of adverse drug events in two large academic long-term care facilities," by Dr. Gurwitz, Terry S. Field, D.Sc., James Judge, M.D., and others, in the March 2005 American Journal of Medicine 118, pp. 251-258.

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