Prescriber and staff inexperience may lead to a false sense of security; that when technology suggests a course of action, errors are avoided. Shortcut or default selections can override non-standard medication regimens for elderly or underweight patients, resulting in toxic doses. CPOE and automated drug dispensing were identified as a cause of error by 84% of over 500 health care facilities participating in a surveillance system by the United States Pharmacopoeia.[40] Irrelevant or frequent warnings can interrupt work flow.