"Relationships Between Ambient Sounds and the Accuracy of Pharmacists' Prescription-Rilling Performance", (c) Flynn EA, Barker KN, Gibson JT, Human Factors in Health Care, December 1996

Abstract

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.

Design: Cross-sectional descriptive study.

Settings: Chain, independent, and health-system pharmacies (located in hospitals or managed care organizations).

Participants: Pharmacy staff at randomly selected pharmacies in each city who accepted an invitation to participate.

Intervention: 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 order).

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 important.

Conclusion: Dispensing 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 year.

Introduction

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. ^[1] This 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 10%.^[2-9] 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 United States.^[10]

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 Financing Administration).^[11]

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:^[12]

• 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 required.
• Ability to communicate errors is not required.
• 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.