Abstract. Objectives:To determine the frequency of potentially inappropriate medication selection for older persons presenting to the ED, the most common problematic drugs, risk factors for suboptimal medication selection, and whether use of these medications is associated with worse outcomes. Methods: The authors performed a prospective cohort study of 898 patients 65 years or older who presented to an urban academic ED in 1995 and 1996. Seventy-nine percent of the patients were African-American and 43% did not graduate from high school. Potentially inappropriate medications and adverse drug-disease interactions were identified using the 1997 Beers explicit criteria for elders. During the three months after the initial visit, revisits to the ED or hospital, death, and changes in health-related quality of life were analyzed as measured by validated questions adapted from the Medical Outcomes Study. Results: Upon presentation, 10.6% of the patients were taking a potentially inappropriate medication, 3.6% were given one in the ED, and 5.6% were prescribed one upon discharge from the ED. The most frequently prescribed potentially inappropriate medications in the ED were diphenhydramine, indomethacin, meperidine, and cyclobenzaprine. Emergency physicians added potentially inappropriate medications most often to patients with discharge diagnoses of musculoskeletal disorder, back pain, gout, and allergy or urticaria. Potentially adverse drug-disease interactions were relatively uncommon at presentation (5.2%), in the ED (0.6%), and on discharge from the ED (1.2%). Potentially inappropriate medications and adverse drug-disease interactions prescribed in the ED were not associated with higher rates of revisit to the ED, hospitalization, or death, but were correlated with worse physical function and pain. However, confidence intervals were wide for analyses of revisits and death. Conclusions: Suboptimal medication selection was fairly common and was associated with worse patient-reported health-related quality of life. Key words: emergency services; aging; drugs; pharmacology; outcomes; quality of care. ACADEMIC EMER-GENCY MEDICINE 1999; 6:1232-1242 A DVERSE drug reactions are common and expensive. For example, a recent meta-analysis estimated that 6.7% of hospitalized patients have serious adverse drug reactions.1 In the outpatient setting, rates of adverse drug reactions have ranged from 1.7% to 50.6%.2 Costs associated with adverse drug events in a typical tertiary care hospital have been approximated to be $1.1-5.6 million per year, 3,4 and drug-related morbidity and mortality have been estimated to cost $76.6 billion annually in the ambulatory setting.5 Therefore, clinicians, administrators, and policymakers have become interested in what system factors contribute to adverse drug reactions and how provider practices around medication prescribing can be improved. 6,7 Several factors place older persons at especially high risk for iatrogenic complications of medication use. The normal aging process is associated with ...
