ABSTRACT
<b>Objective: </b>Similarity in drug appearance is one of the major environmental factors influencing dispensing errors, such as picking the wrong medication (picking error). The purpose of this study is to verify if the index values of appearance similarity calculated objectively for multiple-specification drugs are the factors of picking error.<br><b>Methods: </b>Four variables (number of total prescription, deviation of prescriptions between the specifications, sheet size, and color similarity of the sheet surface) were calculated. The number of total prescription and deviation of prescriptions were extracted from the dispensing system. Sheet size and color similarity were calculated, respectively, from the area ratio and by the Histogram Intersection method using the press through package (PTP) sheet image. To evaluate the relationship between the picking error rate and these four variables, univariate and multivariate analyses were performed.<br><b>Results: </b>The number of total prescription and the deviation of prescriptions were not significant factors. In contrast, sheet size and color similarity significantly influenced the picking error rates.<br><b>Conclusion: </b>Similarity in appearance between multiple-specification drugs is a risk factor of picking error. When the multiple-specification pair has the same sheet size or high color similarity, one needs to be caution of picking error. Further, in the pharmaceutical industry, to reduce the risk of dispensing errors, it is desirable to carry out the devise to enhance the identity of each specification.
ABSTRACT
<b>Objective: </b>Taking the wrong medicine or medication error is a serious concern to patient safety. The aim of this study was to statistically survey the relation between the placement of drugs on medicine shelf and the occurrence of error in taking a medicine.<br><b>Methods: </b>The study comprised 2 groups. The incident group contained 43 cases that were erroneously taken in the Obihiro Kosei General Hospital. The control group contained 43 drug pairs matched by the similarity index of the drug names from among the drugs used in the hospital at random. The similarity index of drug names was based on 10 quantitative indicators. The distance of medicine shelf arrangement was represented by three variables: the horizontal distance, the vertical distance and the distance of shelf block. Conditional logistic regression analyses of the occurrence of medication errors were performed by evaluating the three variables of the distance factor and their interaction for error in taking a similar-sounding named drugs.<br><b>Results: </b>Conditional logistic regression analysis revealed that the vertical distance (OR: 0.64, 95%CI: 0.42-0.99) and the distance of the shelf block (OR: 0.74, 95%CI: 0.57-0.97) were significant risk-reduction factors of medication errors. Four variables were extracted as the most suitable logistic regression model in terms of the interaction between them. As the interaction between 3 variables (the horizontal distance, the vertical distance and the distance of shelf block) was significant (OR: 0.93, 95%CI: 0.86-0.99), they may be considered as synergistic risk-reduction factors. Moreover, the horizontal distance was found to be a risk-enhancement factor (OR: 1.52, 95%CI: 0.93-2.48).<br><b>Discussion: </b>In order to reduce the risk of medication errors due to similar-sounding drug names, placement of drug on the medicine shelf should take into consideration the three coordinates of the distance factor.
ABSTRACT
<b>Objective: </b>Similarity of drug names is one factor of dispensing incidents. The aim of this study was to survey the relation between sensual similarities of drug names and the occurrence of taking errors for pharmacists who actually prepare medicine.<br><b>Methods: </b>A pair of drugs (15 incident pairs and 104 control pairs) was displayed on a computer screen at random. The subject’s task was to determine the sensual similarity of them. Thirteen pharmacists who prepared these pairs and caused their incidents participated in the experiment.<br><b>Results: </b>The result showed that the sensual similarity of drug names of incident pairs was found to be highly significant in comparison to one of the control pairs [<i>p</i>=0.026]. However, the similarity in incident pairs is not necessarily high. It was suggested that the similarity of drug name was not the only factor of taking error. Multiple linear regression analyses of the sensual similarity in control pairs were performed, in which 10 variables were reported as quantitative indicators of similarity of drug name and were able to be measured on the internet. The correlation was good [<i>R</i><sup>2</sup>=0.828]. However, this regression model was not useful when adjusting to incident pairs. In incident pairs, the similarity value calculated by the regression model was lower than the measured sensual similarity.<br><b>Conclusion: </b>The result suggested that measured sensual similarity includes other risk factors of taking error, such as appearance similarity and/or efficacy similarity and/or short distance arrangement. It seemed that the pharmacist’s ability complicated the factor of taking error.