OBJECTIVE: To investigate the causes of irrational outpatient prescriptions in a hospital in Beijing in 2019

and to perform Pareto chart analysis

so as to provide reference for clinical rational drug use.METHODS: The outpatient prescriptions were randomly sampled for rationality review at a rate of 1%.The types of problems in the irrational prescriptions were analyzed by Pareto chart.RESULTS: A total of 18 206 outpatient prescriptions were selected

including 1 358（ 7.46%） irrational prescriptions.There were 11 kinds of irrational prescriptions in this hospital

including 2 main factors

2 secondary factors and 7 general factors.Inappropriate indications

excessive prescriptions

improper usage and dosage and repeated medication were the main factors that lead to irrational prescriptions in the outpatient department of the hospital.CONCLUSIONS: The application of Pareto chart analysis can simply and intuitively reflect the main factors of irrational outpatient prescription in the hospital

prescription behavior of clinicians should be standardized clinically

and the hospital should actively promote the pre-review of prescriptions to ensure rational clinical drug use.