Background: Transition between hospital and ambulatory care is a delicate step involving several healthcare professionals and presenting a considerable risk of drug-related problems.

Objective: To investigate pharmaceutical interventions made on hospital discharge prescriptions by community pharmacists.

Method: This observational, prospective study took place in 14 community pharmacies around a Swiss acute care hospital. We recruited patients with discharge prescriptions (minimum three drugs) from the internal medicine ward of the hospital. The main outcome measures were: number and type of pharmaceutical interventions made by community pharmacists, time spent on discharge prescriptions, number of medication changes during the transition of care.

Results: The study included 64 patients discharged from the hospital. Community pharmacists made a total of 439 interventions; a mean of 6.9 ± 3.5 (range 1-16) interventions per patient. All of the discharge prescriptions required pharmaceutical intervention, and 61 (95%) necessitated a telephone call to the patients' hospital physician for clarifications. The most frequent interventions were: confirming voluntary omission of a drug (31.7%), treatment substitution (20.5%), dose adjustment (16.9%), and substitution for reimbursement issues (8.8%). Roughly half (52%) of all discharge prescriptions required 10-20 min for pharmaceutical validation. The mean number of medication changes per patient was 16.4: 9.6 changes between hospital admission and discharge, 2.6 between hospital discharge and community pharmacy, and 4.2 between community pharmacy and a general practitioner's appointment.

Conclusion: Hospital discharge prescriptions are complex and present a significant risk of medication errors. Community pharmacists play a key role in preventing and identifying drug-related problems.