Beginning on January 1, 1994, each hospital in this state shall provide a diagnosis code for the external cause of an injury, poisoning, or adverse effect for every patient discharged from a hospital, receiving outpatient services, or released from observation for whom such a code would be appropriate. The diagnosis code shall be used in addition to other codes required under federal or state statute, rule, or regulation. The diagnosis code shall be the same as the code required by the International Classification of Diseases, Ninth Revision, Clinical Modification System, or its most recent revision, and shall be entered on the hospital uniform billing form.