Abstract
OBJECTIVE: To evaluate the frequency of medication errors using a multidisciplinary approach, to classify these errors by type, and to determine how often medication errors are associated with adverse drug events (ADEs) and potential ADEs.
DESIGN: Medication errors were detected using self-report by pharmacists, nurse review of all patient charts, and review of all medication sheets. Incidents that were thought to represent ADEs or potential ADEs were identified through spontaneous reporting from nursing or pharmacy personnel, solicited reporting from nurses, and daily chart review by the study nurse. Incidents were subsequently classified by two independent reviewers as ADEs or potential ADEs.
SETTING: Three medical units at an urban tertiary care hospital.
PATIENTS: A cohort of 379 consecutive admissions during a 51-day period (1,704 patient-days).
INTERVENTION: None.
MEASUREMENTS AND MAIN RESULTS: Over the study period, 10,070 medication orders were written, and 530 medications errors were identified (5.3 errors/100 orders), for a mean of 0.3 medication errors per patient-day, or 1.4 per admission. Of the medication errors, 53% involved at least one missing dose of a medication; 15% involved other dose errors, 8% frequency errors, and 5% route errors. During the same period, 25 ADEs and 35 potential ADEs were found. Of the 25 ADEs, five (20%) were associated with medication errors; all were judged preventable. Thus, five of 530 medication errors (0.9%) resulted in ADEs. Physician computer order entry could have prevented 84% of non-missing dose medication errors, 86% of potential ADEs, and 60% of preventable ADEs.
CONCLUSIONS: Medication errors are common, although relatively few result in ADEs. However, those that do are preventable, many through physician computer order entry.
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References
Brennan TA, Leape LL, Laird N, et al. Incidence of adverse events and negligence in hospitalized patients: results from the Harvard Medical Practice Study I. N Engl J Med. 1991;324:370–6.
Steel K, Gertman PM, Crescenzi C, Anderson J. Iatrogenic illness on a general medical service at a university hospital. N Engl J Med. 1981;304:638–42.
Grymonpre RE, Mitenko PA, Sitar DS, et al. Drug-associated hospital admissions in older medical patients. J Am Geriatr Soc. 1988;36:1092–8.
Classen DC, Pestotnik SL, Evans RS, Burke JP. Computerized surveillance of adverse drug events in hospital patients. JAMA. 1991;266:2847–51.
Keith MR, Bellanger-McCleery RA, Fuchs JE Jr. Multidisciplinary program for detecting and evaluating adverse drug reactions. Am J Hosp Pharm. 1989;46:1809–12.
Edlavitch SA. Adverse drug event reporting. Improving the low US reporting rates. Arch Intern Med. 1988;148:1499–503.
Bates DW, Leape LL, Petrycki S. Incidence and preventability of adverse drug events in hospitalized adults. J Gen Intern Med. 1993;8:289–94.
Leape, LL. Brennan TA, Laird NM, et al. The nature of adverse events in hospitalized patients: results from the Harvard Medical Practice Study II. N Engl J Med. 1991;324:377–84.
Melmon KL. Preventable drug reactions—causes and cures. Sem Med Beth Israel Hosp. 1971;284:1361–7.
Lesar TS, Briceland LL, Delcoure K, Parmalle JC, Masta-Gornic V, Pohl H. Medication prescribing errors in a teaching hospital. JAMA. 1990;263:2329–34.
Folli HL, Poole RL, Benitz WE, Russo JC. Medication error prevention by clinical pharmacists in two children’s hospitals. Pediatrics 1987;79:718–22.
Beers MH, Ouslander JG, Fingold SF, et al. Inappropriate medication prescribing in skilled-nursing facilities. Ann Intern Med 1992;117:684–9.
Neville RG, Robertson F, Livingstone S, Crombie IK. A classification of prescription errors. J R Coll Gen Pract. 1989;39:110–2.
ASHP guidelines on preventing medication errors in hospitals. Am J Hosp Pharm. 1993;50:305–14.
Rheinstein PH, McGinnis TJ. Medication errors. Am Fam Physician. 1992;45:2720–2.
Zellmer WA. Medication error versus medication misadventure—what’s in a name? Am J Hosp Pharm. 1993;50:315–8.
Cohen MR, Davis NM. Dispensing the wrong medication. Am Pharm. 1992;NS32:28–9, 32.
Schroeder CG, Pierpaoli PG. Direct order entry by physicians in a computerized hospital information system. Am J Hosp Pharm. 1986;43:355–9.
Tierney WM, Miller ME, Overhage JM, McDonald CJ. Physician in-patient order writing on microcomputer workstations. Effects on resource utilization. JAMA. 1993;269:379–83.
Dubous RW, Brook RH. Preventable deaths: who, how often, and why. Ann Intern Med. 1988;190:582–9.
Feinstein AR. Clinical Epidemiology: The Architecture of Clinical Research. Philadelphia: W.B. Saunders, 1985.
Fleiss JL. Statistical Methods for Rates and Proportions. New York: John Wiley and Sons, 1981.
SAS Institute Inc. Release 6.03. Cary, NC: SAS, 1988.
Blum KV, Abel SR, Urbanski CJ, Pierce JM. Medication error prevention by pharmacists. Am J Hosp Pharm. 1988;45:1902–3.
Raju TN, Kecskes S, Thornton JP, Perry M, Feldman S. Medication errors in neonatal and pediatric intensive-care units. Lancet. 1989;2:374–6.
Shaughnesy AF, Nickel RO. Prescription-writing patterns and errors in a family medicine residency program. J Fam Pract. 1989;29:290–5.
Anastasio GD, Sigmon JL Jr. Prescription-writing errors [letter; comment]. J Fam Pract. 1990;30:108.
Anastasio GD, White TR, Fries JC. Computerized Prescription Inventory Program for the Education of Residents (PIPER). J Fam Pract. 1986;23:598–600.
Betz RP, Levy HB. An interdisciplinary method of classifying and monitoring medication errors. Am J Hosp Pharm. 1985;42:1724–32.
Simborg DW, Derewicz HJ. A highly automated hospital medication system. Five years’ experience and evaluation. Ann Intern Med 1975;83:324–6.
Hawkey CJ, Hodgson S, Norman A, Daneshmend TK, Garner ST. Effect of reactive pharmacy intervention on quality of hospital prescribing. BMJ. 1990;300:986–90.
Means BJ, Derewicz HJ, Lamy PP. Medication errors in a multidose and a computer-based unit dose drug distribution system. Am J Hosp Pharm. 1975;32:186–91.
Pang F, Granat JA. Missing medications associated with centralized unit dose dispensing. Am J Hosp Pharm. 1975;32:1121–3.
Kitrenos JG, Glue K, Stotter ML. Analysis of missing medication episodes in a unit dose system. Hosp Pharm. 1979;14:642, 648, 652–3.
Grabowski B. Missing medications in a unit-dose system: quality assurance. Hosp Pharm. 1987;22:679–80.
Churchill WW, Gavin TJ, Souney PF, Stachowski JS. Source of missing doses in a decentralized unit dose system: a quality assurance review. Hosp Pharm. 1988;23:453–6.
Evans RS, Classen DC, Stevens LE, et al. Using a hospital information system to assess the effects of adverse drug events. Proc Annu Symp Comput Appl Med Care. 1994;17:161–6.
Massaro TA. Introducing physician order entry at a major academic medical center: I. Impact on organization culture and behavior. Acad Med. 1993;68:20–5.
Massaro TA. Introducing physician order entry at a major academic medical center: II. Impact on medical education. Acad. Med. 1993;68:25–30.
Ellinoy BJ, Bilroy G. Another step toward computerized order entry. Am J Hosp Pharm. 1990;47:2460–1.
Kawahara NE, Jordan FM. Influencing prescribing behavior by adapting computerized order-entry pathways. Am J Hosp Pharm. 1989;45:1798–801.
Poikonen J. Computerized order entry: hospital versus pharmacy-based systems. Am J Hosp Pharm. 1990;47:2461–2.
Preece JF, Ashford JR, Hunt RG. Writing all prescriptions by computer. J R Coll Gen Pract. 1984;34:655–7.
Donald JB. On line prescribing by computer. BMJ. 1986:292; 937–9.
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Received/mm the Division of General Medicine, Departments of Medicine and Pharmacy, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts.
Supported in part by the Risk Management Foundation. Dr. Bates is the recipient of National Resource Service Award 1 F32 HS00040-01 from the Agency for Health Care Policy and Research.
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Bates, D.W., Boyle, D.L., Vliet, M.B.V. et al. Relationship between medication errors and adverse drug events. J Gen Intern Med 10, 199–205 (1995). https://doi.org/10.1007/BF02600255
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DOI: https://doi.org/10.1007/BF02600255