Pharmacists' Dispensing Accuracy in a High-Volume Outpatient Pharmacy Service: Focus on Risk Management

Abstract

A 12-day peer-review audit was performed in the outpatient pharmacy of a large teaching hospital. The audit process was not masked, that is, the pharmacists were aware of the peer-review evaluation. During the 12-day period, 9394 prescription forms and their corresponding pharmaceutical products were examined manually before being delivered to the patient. A total of 1165 (12.4 percent) dispensing errors were detected, with 141 (1.5 percent) of these considered potentially serious. Seventy-six prescriptions contained two errors and four prescriptions contained three. A linear relationship (r2 = 0.78; p less than 0.001) existed between the number of potentially serious errors and the total number of prescriptions filled. There were no statistically significant differences in the dispensing-error rate for the eight pharmacists audited. There was a trend for the number of pharmacist-hours containing at least one potentially serious dispensing error to increase as the prescription-filling rate accelerated. Outpatient pharmacies with high volumes should set a limit to the number of prescriptions filled by their pharmacists and should experiment with quality assurance systems to reduce dispensing errors and subsequent legal liabilities.

Incidence, type and causes of dispensing errors: a review of the literature

“…[3,33-37,39,41-44,47-50,52,54,56-61, 63,64,70,71] The most common error categories identified in the research papers were dispensing the wrong drug (100%, n = 39), strength (95%, n = 37), dosage form (77%, n = 30) and quantity (69%, n = 27), and labelling drugs with the wrong directions (77%, n = 30). Errors arising during the screening of prescriptions for legal validity and clinical safety, [49,50,54] completing controlled drug documentation [43,50,54,61] and reconstituting and preparing extemporaneous medicines [63,65] were included in a few research papers despite being typically subject to separate risk-management procedures. [39] Dispensing error rate Forty-five reviewed papers reported the dispensing error rate in community and/or hospital pharmacy (Tables 7 and 8).…”

“…[39] Dispensing error rate Forty-five reviewed papers reported the dispensing error rate in community and/or hospital pharmacy (Tables 7 and 8). [14,15,17,19,21,[24][25][26][27][28]30,32], [3,[33][34][35]38,39,[43][44][45][46][47][49][50][51][52][53][54][55][56][57][59][60][61][62][63][64][65][66][67][68][69][70][71][72] However, only 18% (n = 8) of these papers clearly defined the calculation of dispensing-error rate. [15,28,…”

“…[49,50,52,54,57,58,60,[63][64][65] All nine papers reported the types of unprevented dispensing incidents but one paper [65] also reported the types of prevented dispensing incidents. The most common unprevented dispensing incidents associated with both manual and automated dispensing systems were supply of the wrong drug, dosage form, strength and quantity, and printing the wrong directions on the label (Figure 7).…”

“…The most common unprevented dispensing incidents associated with both manual and automated dispensing systems were supply of the wrong drug, dosage form, strength and quantity, and printing the wrong directions on the label (Figure 7). [49,50,52,54,57,58,[63][64][65] The most common prevented dispensing incidents were supply of the wrong quantity (62%, n = 2471), drug (11%, n = 451), strength (10%, n = 419) and dosage form (8%, n = 330). [65] Error types in Australia…”

“…Guernsey and colleagues [50] objectively measured the impact of dispensary workload on unprevented dispensing incidents in a US hospital outpatient pharmacy. They concluded that a linear relationship existed between the number of prescriptions dispensed and potentially serious W r o n g p a t i e n t n a m e W r o n g q u a n t i t y o n l a b e l O t h e r Figure 6 Most common types of prevented dispensing incidents reported by UK hospital pharmacies with manual [3,[33][34][35]43,46,72] and automated [45,46,72] dispensing systems.…”