Dispensing errors in a Rio de Janeiro tertiary hospital: incidence, types, and causes / Erros de dispensação em hospital terciário do Rio de Janeiro: incidência, tipos e causas

Objective: In this study, the drug dispensing system of a tertiary care center was analysed, with the purpose of identifying the occurrence of dispensing errors, their types, causes, and the role of double checking in prevention. The main factors that contribute for the errors and the recommendations to avoid them have been evaluated from the perspective of the professionals involved in the dispensation process. Methods: 1,077 prescriptions were assessed in a 6-month  period. The errors were recorded and corrected before the medication left the pharmacy. Each pharmaceutical unit dispensed was considered as a possibility of error. The results were analyze through descriptive statistics (average, median, standard deviation, coefficient of variation, and frequencies). In the second step of the research, the opinion of the professionals directly involved with dispensing  about causes and consequences of the errors was assessed through a questionnaire with  open and closed questions to explore the factors and causes of errors. Results: A 4.5% rate of dispensing errors inside the pharmacy was observed , during the double-check process. The rate observed when the medicines arrived at the admission units was of 0.37%.  The most frequent class of errors in dispensing was drug omission (62.9%), followed by dose added errors (11.7%); incorrect time (10.2%); incorrect drug (9.2%), and changed dosage form (6.4%). We found a direct relationship between the number of dispensed items during a shift and the number of dispensing errors (ρ=0,844). The schedule for team shifts  influenced the error rate (p=0,016). Conclusion: Knowing the dispensing error profile is crucial for promoting behaviour changes and to define adequated error barriers.