Duke University Hospital 7-point severity scoring system for patient harm
| Score | Severity definitions |
| 0 | Caught before reached patient, but a system failure occurred |
| 1 | Reached patient, but there were no patient effects or consequences to medication use system; single dose or infusion problem >4 h |
| 2 | Reached patient, there were no detectable patient effects, but change(s) occurred in medication schedule dosing, duration or monitoring; multiple doses or infusion problem >4 h |
| 3 | Transient adverse patient effects occurred that required some corrective therapy, increased length of stay by 1 to 2 days, or resulted in laboratory values, vital signs or medication effects outside desirable parameters. A severity of 3 or greater is considered an adverse drug event if there is evidence that a drug is at fault. |
| 4 | Significant adverse patient effects occurred that required aggressive intervention, such as code, intubation, transfer to intensive-care unit, interventional drug therapy or increased length of stay >2 days |
| 5 | Permanent adverse patient effects occurred, such as paralysis, brain damage, disability or loss of limb, organ or bodily function |
| 6 | Patient death |