Rationale, aims and objectives Medication discrepancies are frequent at hospital admission and have the potential to cause harm. However, the potential risk factors concerning unintentional medication discrepancies in China is still unclear. The aim of the study was to determine the frequency of unintentional medication discrepancies and the associated risk factors and evaluate the potential harms of errors prevented.

Method This Prospective interventional study was carried out in four internal medicine wards including cardiology department, nephrology department, endocrinology department and respiratory medicine in a grade A tertiary university teaching hospital in China. Medication reconciliation process was performed at admission to the departments between 2019 Feb 1st and 2019 Aug 31st by clinical pharmacists trainees. And the expert panel evaluated all unintentional medication discrepancies to determine their potential harm. Associations between unintentional medication discrepancies and factors involved were evaluated.

Results In general, 321 patients were enrolled (mean age 59.7±15.2 years; 176 men). The reconciliation process identified 511 medication discrepancies, with 98 (74 patients) being unintentional medication discrepancies. The most frequent unintentional medication discrepancies type was omission (40.8%), followed by incorrect dose (25.5%), and 73.5% were likely to cause moderate to significant harm and complications to patients. Polypharmacy and 2 or more chronic diseases at admission associated with unintentional medication discrepancies in a multivariable analysis after univariate adjustment.

Conclusions Pharmacy-led medication reconciliation on admission and pharmacist trainees involvement can diminish unintentional medication discrepancies effectively. Patients taking multiple drugs and experiencing more than two chronic diseases were proved to be specifically at risk.