Category A represents circumstances or events that have the capacity to cause error, category B indicates that a medication error occurred but it did not reach the patient, categories C and D designate medication errors that reached the patient but did not result in patient harm. The varying level of patient harm is reflected in categories E, F, G and H. Category E refers to errors that may have contributed to or resulted in temporary harm to the patient and required intervention. Category F contains errors that may have contributed to or resulted in temporary harm to the patient and required initial or prolonged hospitalization. Category G labels all errors that may have contributed to or resulted in permanent patient harm. Category H errors require intervention necessary to sustain life and any medication error that resulted in, or may have contributed to a patient’s death is classified as category I