Abstract: Objective To determine the nature and types of medication errors and prevent potential errors. Methods Medication incidents reported from October 2012 to December 2016 in a tertiary general hospital were assessed and analysed by a clinical pharmacist. Analysis projects included category, type, triggering factor of ME, and proportion of persons who triggered or detected ME. Results 251 medication errors were reported, proportions of ME of category A, B, C, D, E, and F were respectively 3.98%, 33.86%, 45.42%, 11.95%, 3.98%, and 0.80%, ME of category G, H, and I have not been reported. 251 errors of type were noted. Therein, wrong patient was the highest proportion which reached 23.51%, the errors of omitted administration, dosage, wrong medication and indication respectively accounted for 23.11%, 11.16%, 8.37% and 7.17%. In 251 reports of ME, 329 triggering factors were noted. The most important factor was staff-related factors which reached 42.24%, the main reasons were inadequate training and inexpert skill. Omission error was the most common factor, accounted for 21.58%. In terms of the persons that triggered ME, the proportion of nurse was 84.47%, especially for student nurses and primary nurses (76.10%). Nurses and patient's family members were the main persons who detected medication errors, respectively accounted for 63.75% and 21.91%. Conclusion Medication errors are frequent, the identification of its determinants helps to undertake designed interventions. There is a need to establish ME reporting system to reduce its incidence and improve patient care and safty.

Key words: medication errors, reason analysis, hospitalized patients