MEDICATION-PRESCRIBING ERRORS IN A TEACHING HOSPITAL - A 9-YEAR EXPERIENCE

Background: Improved understanding of medication-prescribing errors sh ould be useful in the design of error prevention strategies. Objective : To report analysis of a 9-year experience with a systematic program of detecting, recording, and evaluating medication-prescribing errors in a teaching hospital. Methods: All medication-prescribing errors wit h potential for adverse patient outcome detected and averted by staff pharmacists from January 1, 1987, through December 31, 1995, were syst ematically recorded and analyzed. Errors were evaluated by type of err or, medication class involved, prescribing service, potential severity , time of day, and month. Data were analyzed to determine changes in m edication-prescribing error frequency and characteristics occurring du ring the 9-year study period. Results: A total of 11 186 confirmed med ication-prescribing errors with potential for adverse patient conseque nces were detected and averted during the study period. The annual num ber of errors detected increased from 522 in the index year 1987 to 21 15 in 1995. The rate of errors occurring per order written, per admiss ion, and per patient-day, all increased significantly during the study duration (P<.001). Increased error rates were correlated with the num ber of admissions (P<.001). Antimicrobials, cardiovascular agents, gas trointestinal agents, and narcotics were the most common medication cl asses involved in errors. The most common type of errors were dosing e rrors, prescribing medications to which the patient was allergic, and prescribing inappropriate dosage forms. Conclusions: The results of th is study suggest there may exist a progressively increasing risk of ad verse drug events for hospitalized patients. The increased rate of err ors is possibly associated with increases in the intensity of medical care and use of drug therapy. Limited changes in the characteristics o f prescribing errors occurred, as similar type errors were found to be repeated with increasing frequency. New errors were encountered as ne w drug therapies were introduced. Health care practitioners and health care systems must incorporate adequate error reduction, prevention, a nd detection mechanisms into the routine provision of care.