Occurrence of dispensing errors and efforts to reduce medication errors at the Central Arkansas Veteran's Healthcare System.

Background: Medical errors have received national attention in the past few years, largely due to the Institute of Medicine's (IOM) 1999 report, which found that over one million injuries and nearly 100,000 deaths occur annually in the US as a result of medical errors.

Purpose: The purpose of this study was to examine the type and severity of dispensing errors reported by pharmacy services at the Central Arkansas Veteran's Healthcare System from October 1997 through September 2001 and to examine the efforts implemented by the Central Arkansas Veteran's Healthcare System to reduce overall medication-related errors.

Methods: Dispensing error reports for the Central Arkansas Veteran's Healthcare System were obtained for October 1997 to September 2001. Dispensing errors were tabulated in the Statistical Package for the Social Sciences (SPSS) according to the pharmacy section, type of error (wrong drug, wrong dose, wrong patient and 'other') and severity of error (minor, significant, major and unrated). Data were explored using descriptive statistics, chi2, independent sample t-tests and Pearson's correlation. Information on error reduction efforts was obtained from pharmacy administrative services.

Results: A total of 82 dispensing errors were reported from eight different pharmacy sections for the time period examined. Errors included 31 wrong drugs, 21 wrong doses, 24 wrong patients and six 'other' errors. The number of errors, according to severity, included 29 unrated, 30 minor, 21 significant and two major errors. Both major errors were due to wrong drug selection. In total, the highest number of errors occurred at the North Little Rock Ambulatory Care Pharmacy (39 errors) and the Little Rock Ambulatory Care Pharmacy (24 errors). Wrong drug and wrong dose dispensing errors were not significantly different among the pharmacy sections. Wrong patient selection was significantly different among pharmacy service sections. Wrong patient selection, wrong drug, and wrong dose were all significantly correlated with unrated severity, minor severity, and significant severity. Significant correlations were also found between wrong drug, wrong dose and wrong patient selection. There were no significant correlations between wrong patient selection and major severity, or other errors. chi2 analysis found significant differences in expected frequency among errors for wrong drug, wrong dosage, wrong patient and other errors. Significant differences were also found in expected frequencies between unrated, minor, significant and major errors.

Discussion: Although the major dispensing errors were not statistically different according to pharmacy services sections and not significantly correlated with any other categories, they both involved the selection of the wrong drug, which was also the most common error. In contrast, the selection of the wrong patient, the second most common error, was statistically different among pharmacy sections and was significantly correlated with all other dispensing type and severity of error except major severity and other errors.

Conclusion: Focusing error reduction efforts on selection of the correct drug and correct patient would likely yield the best results in reducing dispensing errors since these errors combined accounted for 55 (67.1%) of the 82 reported errors.