Objective: 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.
Methods: 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.
Results: 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).
Discussion: 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.

Purpose: This review was performed to investigate the state of fatigue in patients with heart failure. Methods: A literature search of ICHUSHI, PubMed, PsycINFO, and CINAHL was conducted to identify articles published from database inception to March 2018. In total, one hundred and nineteen papers were included in the present review. Results: Two Japanese-language papers and one hundred and seventeen English-language papers were analyzed. None of the papers contained definitions of fatigue specific to patients with heart failure. The prevalence of fatigue was 50% to 94% according to a scale that measured not only fatigue but also quality of life. The reports indicated that severe heart failure, low exercise capacity, symptoms of depression, older age, and female sex are related to the severity of fatigue and that the severity of fatigue influences the prognosis. Conclusions: The results of our review revealed a lack of evidence for measurement of fatigue specific to patients with heart failure. Further studies are needed to establish a method by which to adequately evaluate fatigue in patients with heart failure.