1. Although rates of dispensing errors are generally low, further improvements in pharmacy distribution systems are still important because pharmacies dispense such high volumes of medications that even a low error rate can translate into a large number of errors. 2. From the perspective of pharmacy organization and quality assurance, pharmacists should intensify their checking of prescriptions, in order to reduce prescription errors, and should implement strategies to communicate adequately with patients, in order to prevent administration errors. More and better studies are still needed in these areas. 3. More research is also required into: dispensing errors in out-patient health-care settings, such as community pharmacies in the USA and Europe; dispensing errors in hospitals and out-patient health-care settings in middle-and low-income countries; and the underlying causes of dispensing errors.Six main types of medication error can occur in the chain of pharmacological and pharmaceutical patient care: prescribing faults, prescription errors, transcription errors, dispensing errors, administration errors, and 'across settings' errors [1]. In this article we focus on dispensing errors.
Definition of a dispensing errorA dispensing error is a discrepancy between a prescription and the medicine that the pharmacy delivers to the patient or distributes to the ward on the basis of this prescription, including the dispensing of a medicine with inferior pharmaceutical or informational quality [1-6]. Table 1 shows the categories of dispensing errors [1,2,3,6,7]. If dispensing errors are considered from the perspective that the quality of all pharmacy care activities should be assured by the pharmacist, this list can be extended by the addition of three other categories: failure to detect and correct a prescribing error before dispensing; failure to detect a manufacturing error before dispensing; and failure to provide adequate patient counselling in order to prevent administration errors. These categories arise in other segments of the pharmaceutical patient care chain, but they are nevertheless important when one strives for a full assessment of the pharmacy's performance [8,9].
Categories of dispensing error
Recent studies of dispensing errorsWe searched Pubmed on-line using the keywords 'dispensing errors' and related search terms. We also searched manually for related articles in the reference lists of the studies we retrieved and selected. We used only studies that were published in English after 2003. Table 2 shows the rates of dispensing errors and different subtypes of dispensing errors [2-4, 6, 7, 10-16, Dutch Association of Hospital Pharmacists (NVZA): unpublished data]. The rates of dispensing errors were 0-45%. The highest rates of dispensing errors were in studies in which a researcher observed the dispensing process or checked and compared the dispensed medicines against the relevant prescriptions. Some studies used a self-reporting system to count the number of dispensing errors. These studies did not pro...