Background Discharge from hospital is a high-risk period for medicines errors. Unintentional medicines discrepancies may contribute to drug-related problems at home.

Purpose To identify and assess the clinical impact of unintentional medicines discrepancies at hospital discharge in order to reduce them.

Material and methods Patients admitted to the internal medicine department in August 2014 were included in this prospective study. Any differences between the patient’s current home medicines (based on pre-admission prescriptions and medical history in the patient’s file) and the discharge prescription were listed. Discrepancies were categorised with physicians as intentional or unintentional.

The clinical impact of unintentional discrepancies was assessed by two physicians and one pharmacist as may having no, minor, significant or major consequences.

Results 62 patients were included (52.3% men – average age: 73.1 ± 15.5 years). The average number of medicines per patient was 6.1 ± 3.9.

295 discrepancies were identified at discharge: 80.3% intentional and 19.7% unintentional.

The unintentional discrepancies were classified as 43.1% (25) missing chronic medicine, 8.6% (5) addition of a new drug, 8.6% (5) different dose, 15.5% (9) different frequency, 20.7% (12) change to therapeutic equivalent and 3.5% (2) other.

21.8% (12) of discrepancies may have had significant consequences for the patient, 50.9% (28) minor consequences and 27.2% (15.7) no impact.

Only 42.3% (124) of intentional discrepancies were documented in discharge letters.

Conclusion Discharge is a particularly vulnerable transitional interface regarding the number of discrepancies and their potential clinical impact.

Omission of chronic medicines and change to therapeutic equivalents – which may be confusing for elderly patients – were the most common discrepancies.

Intentional discrepancies not communicated to family physician can lead to the patient’s care not being changed.

Obtaining a complete picture of medicines at admission is another difficulty due to multiple prescribers.

This study highlights the need for medicines reconciliation to prevent adverse drug events and to improve continuity of care and patient safety.

References and/or acknowledgements No conflict of interest.