[Adverse effects and medication errors: incidence and role of the organization of drug distribution].
The true incidence of adverse drug events is controversial and there are few data concerning the percentage of potentially preventable adverse drug events. Over 2 months, in two internal medicine units, we asked the staff to report adverse drug events. All incidents were evaluated: adverse drug events (preventable and non-preventable) and potential adverse drug events (non-intercepted potential adverse drug events and intercepted potential adverse drug events). The severity, the stage in the process at which the error occurred and the type of error were evaluated by a physician reviewer. Over the 240 admissions, the incidence of adverse drug events is 18 per 1000 patient-days. The system design caused 77 per cent of the incidents. The medication errors occurred at all stages from ordering to administration. Adverse drug events resulting in medication errors (n = 22) were more serious than non-preventable adverse drug events (n = 26) (p = 0.003). A prevention strategy by pharmacovigilance centres (Centres Régionaux de Pharmacovigilance) should target all stages of the drug delivery process.