Medication Errors Observed in 36 Health Care Facilities


Medication Errors Observed in 36 Health Care Facilities

Kenneth N. Barker, PhD; Elizabeth A. Flynn, PhD; Ginette A. Pepper, PhD;
David W. Bates, MD, MSc; Robert L. Mikeal, PhD

Background   Medication errors are a national concern.

Objective  To identify the prevalence of medication errors (doses administered differently than ordered).

Design  A prospective cohort study.

Setting  Hospitals accredited by the Joint Commission on Accreditation of Healthcare Organizations, nonaccredited hospitals, and skilled nursing facilities in Georgia and Colorado.

Participants  A stratified random sample of 36 institutions. Twenty-six declined, with random replacement. Medication doses given (or omitted) during at least 1 medication pass during a 1- to 4-day period by nurses on high medication–volume nursing units. The target sample was 50 day-shift doses per nursing unit or until all doses for that medication pass were administered.

Methods  Medication errors were witnessed by observation, and verified by a research pharmacist (E.A.F.). Clinical significance was judged by an expert panel of physicians.

Main Outcome Measure  Medication errors reaching patients.

Results  In the 36 institutions, 19% of the doses (605/3216) were in error. The most frequent errors by category were wrong time (43%), omission (30%), wrong dose (17%), and unauthorized drug (4%). Seven percent of the errors were judged potential adverse drug events. There was no significant difference between error rates in the 3 settings (P = .82) or by size (P = .39). Error rates were higher in Colorado than in Georgia (P = .04)

Conclusions  Medication errors were common (nearly 1 of every 5 doses in the typical hospital and skilled nursing facility). The percentage of errors rated potentially harmful was 7%, or more than 40 per day in a typical 300-patient facility. The problem of defective medication administration systems, although varied, is widespread.

Author/Article Information

From the Center for Pharmacy Operations and Designs, School of Pharmacy, Auburn University, Auburn, Ala (Drs Barker and Flynn); the School of Nursing, University of Colorado Health Sciences Center, Denver (Dr Pepper); the Division of General Internal Medicine and Primary Care, Brigham and Women’s Hospital, and the Center for Applied Medical Information Systems, Partners Healthcare and Harvard Medical School, Boston, Mass (Dr Bates); and DACE Co, West Monroe, La (Dr Mikeal).

Corresponding author and reprints: Kenneth N. Barker, PhD, Center for Research on Pharmacy Operations and Designs, School of Pharmacy, Auburn University, 128 Miller Hall, Auburn, AL 36849-5506 (e-mail:

Accepted for publication February 13, 2002.

This study was supported by grant 500-96-P605 from the Alabama Quality Assurance Foundation, Birmingham.

We thank Robert M. Cisneros, RPh, MS, for his valuable assistance at 16 sites in Georgia. We appreciate the input and advice of Samuel W. Kidder, PharmD, MPH, pharmacy consultant at Health Care Financing Administration. We thank Linda A. Pfaff, RN, MS, coordinator for operations in Georgia, for her valuable assistance. We also thank Helen Deere-Powell, RPh; Lucian L. Leape, MD; Loriann E. DeMartini, PharmD; G. Neil Libby, PhD, RPh; Richard Shannon, RPh; Robert E. Pearson, RPh, MS; Tejal Gandhi, MD; Rainu Kaushal, MD; and Jeffrey Rothschild, MD, for the various roles they played in the preparation of the manuscript.