Gurwitz and colleagues showed that a complex intervention, aimed at a reduction of drug-related adverse events and medication errors immediately after hospital discharge, did not result in a significant outcome difference between the intervention and control groups. We feel that the intervention lacked standardization, that a better outcome might have been achieved by intervening prior to hospital discharge, that more details about the nature of observed medication errors and acceptance of the intervenor recommendations should have been reported. Also, the number of unpreventable adverse drug events was higher in the intervention (n = 37) than in the control group (n = 27), suggesting a Hawthorne effect. The small number of adverse drug events detected overall points to a low sensitivity of the detection method used. We recommend that future studies be designed differently, including a stronger focus on physician-pharmacist collaboration, patient participation and improved communication between the hospital and general practice.