Background In CHU Mont-Godinne, physicians prescribe medicines through a CPOE system and medicines are then delivered on an individual patient basis by the pharmacy. The amounts are generated according to a ‘limit date system’. The pharmacy faces the problem of considerable amounts of medicines returned.

Purpose To determine the root causes of medicines being returned to a hospital pharmacy.

Materials and methods The study was conducted on the ‘Respiratory & Oncology’ ward and focused on all medicines returned in relation to 31 patients who had been admitted to the unit for a period of 5 weeks. Currently, one out of four medicines supplied to the ‘Respiratory & Oncology’ ward is not administered to the patient and is returned to the pharmacy. Cause analysis was conducted retrospectively and according to a lean approach. It is a structured process used to improve process cycle time through the identification, reduction and elimination of process waste and non-value-added activities. First, The authors determined for each medicine returned to the pharmacy the step of the medication use process where the problem originated: the prescription, dispensing by the pharmacy, picking operation by nurses, administration to the patients and management. Then for each of these steps The authors identified more specific reasons why it had been returned.

Results 1754 returned medicines were analysed. The three main root causes of returned medicines were: a discharge date not recorded in the CPOE system (22.86%), inappropriate use of electronic prescribing (10.15%), late capture of a known discharge date (7.98%).

Conclusions To reduce the number of returned medicines, health professionals using the CPOE systems must be trained appropriately. Once the discharge date of the patients is known, it is imperative to record this information as quickly as possible in the software.