Inappropriate medication administration to the acutely ill elderly: a nationwide emergency department study, 1992-2000.

OBJECTIVES: To determine the national rate and trend of inappropriate medication administration to elderly emergency department (ED) patients. Secondary objectives were to identify risk factors for receiving an inappropriate medication and to determine whether administration is sometimes justified based on diagnosis.

DESIGN: Retrospective analysis of ED visits in the 1992-2000 National Hospital Ambulatory Medical Care Survey. Inappropriate medications identified using Beers' 1997 explicit criteria.

SETTING: EDs of U.S. noninstitutionalized general and short-stay hospitals.

PARTICIPANTS: ED survey patients aged 65 and older.

MEASUREMENTS: Magnitude and rate of administration of 36 medications.

RESULTS: Inappropriate medications were administered in an estimated 16.1 million (95% confidence interval (CI)=14.9-17.3 million) or 12.6% (95% CI=11.6-13.5%) of elderly ED visits from 1992 to 2000. The rate of inappropriate administration was unchanged throughout the study period (P=.40). Six drugs accounted for 70.8% of inappropriate administration: promethazine (22.2%), meperidine (18.0%), propoxyphene (17.2%), hydroxyzine (10.3%), diphenhydramine (7.1%), and diazepam (6.0%). In multivariate analysis, number of ED medications was the strongest predictor, with an odds ratio for two to three medications of 6.0 (95% CI=5.3-6.7) and for four to six medications of 8.1 (95% CI=7.2-9.2). Diagnoses indicating potentially appropriate uses of these medications were rarely present. For example, only 42.4% of patients receiving diphenhydramine and 7.4% receiving hydroxyzine were diagnosed with an allergic process.

CONCLUSION: Elderly ED patients are frequently administered inappropriate medications. Potentially appropriate uses of generally inappropriate drugs cannot account for such administrations. Inappropriate administration rates remain unchanged despite the 1997 publication of explicit criteria.