"Relationships Between Ambient Sounds and the Accuracy of
Pharmacists' Prescription-Rilling Performance", (c) Flynn
EA, Barker KN, Gibson JT, Human Factors in Health Care,
Objectives: To measure
dispensing accuracy rates in 50 pharmacies located in 6
cities across the United States and describe the nature
and frequency of the errors detected.
independent, and health-system pharmacies (located in
hospitals or managed care organizations).
staff at randomly selected pharmacies in each city who
accepted an invitation to participate.
Observation by a pharmacist in each pharmacy for 1 day,
with a goal of inspecting 100 prescriptions for dispensing
errors (defined as any deviation from the prescriber's
Main Outcome Measure:
Dispensing errors on new and refill prescriptions.
Results: Data were
collected between July 2000 and April 2001. The overall
dispensing accuracy rate was 98.3% (77 errors among 4,481
prescriptions; range, 87.2%-100.0%; 95.0% confidence
interval, ± 0.4%). Accuracy rates did not differ
significantly by pharmacy type or city. Of the 77
identified errors, 5 (6.5%) were judged to be clinically
errors are a problem on a national level, at a rate of
about 4 errors per day in a pharmacy filling 250
prescriptions daily. An estimated 51.5 million errors
occur during the filling of 3 billion prescriptions each
The national awakening of
health care professionals to medication safety issues is
evidenced by the reaction to the Institute of Medicine's
report To Err Is Human.
report stimulated discussion of the fundamental questions
"Is there a dispensing error problem?" and "If so, what is
its nature and magnitude?" Answering these questions is
important for identifying needed interventions (e.g.,
automation, training) and justifying their associated
expense. Case studies using observation in outpatient
pharmacies have detected error rates ranging from 0.2% to
Using conservative estimates of a 1% dispensing error rate
and an annual total of 3 billion dispensed prescriptions,
a projected 30 million errors would occur each year in
A measure of the national
dispensing error rate should be of immediate interest to
not only consumers and pharmacists but also to groups,
such as the National Committee for Quality Assurance and
state boards of pharmacy, that are interested in setting a
standard of quality for prescription filling operations.
Although no standard exists for prescription dispensing
errors in the ambulatory setting, a national standard has
been established for medication administration errors in
nursing homes: An error rate exceeding 5% can result in
withholding of reimbursement by the federal Centers for
Medicare & Medicaid Services (formerly the Health Care
The drug distribution system
in the ambulatory care setting consists of the processes
of prescribing, prescription fulfillment, patient
self-administration, and follow-up monitoring. In this
study we focused on errors in the prescription fulfillment
process in chain, independent, and health-system (hospital
and managed care) pharmacies.
We used direct observation to
detect errors because it is recognized as the most
accurate method, detecting many more errors than voluntary
self-reports in hospitals and long-term care facilities.[12-18]
Observation has a number of advantages when used to study
the sensitive subject of medication errors:
Knowledge of the error by the person
involved is not required (they are often not aware that
an error has been made).
Willingness to report the error is
not a factor (there is no threat of disciplinary action
as a result of recording the error using observation).
Remembering to report errors is not
Ability to communicate errors is not
Selective perception of the nurse or
pharmacist is not involved (they may only believe it is
necessary to report serious errors).
Observation has been used to
detect medication administration errors in studies in
hospitals and nursing homes for more than 40 years.