Avoidable Patient Harm and Resulting Liability What would it take to improve our insight into the cost of avoidable patient harm? Medications are the most frequent cause of adverse events in clinical settings. Some of the most devastating drug-related injuries include Steven-Johnson Syndrome, drug-related liver injury or bone marrow failure. These events, however rare, are among those that are very expensive to treat and often leave long-lasting damage. The substantial consequences of adverse drug events are hospital admissions and readmissions, prolonged hospital stay, additional therapeutic interventions and increased demand on staff. For the patient, in addition to all the misery and pain they suffer, adverse drug events mean time away from work, loss of income and additional medical expenses.