Arch Intern Med 2002 (Sept 9); 162 (16): 1897–1903
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 medicationvolume 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
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,
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: firstname.lastname@example.org).
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.