Primary diagnosis codes were grouped for analysis in the following manner. Nine diagnostic groups were defined based on the primary diagnosis code assigned by the paramedic. Trauma/poisoning was defined as all patients with the diagnosis of fracture(s), hemorrhage, hematoma, overdose, poisoning, inhalation, motor vehicle crash, fall, environmental injury, other injury, shooting, stabbing, accident, suicide, assault, fight, amputation, submersion, or burn.Respiratory included all patients with respiratory distress, respiratory failure, pulmonary edema, pneumonia, or tracheal obstruction. Gastrointestinal included any conditions related to the gastrointestinal system including feeding problems. Thecardiac group included all arrythmias, cardiogenic shock, and nontraumatic cardiac arrest. The pain group included all persons with the primary complaint of pain from causes other than trauma such as headache or sickle cell crisis. The neurologic group included unconsciousness (not related to poisoning), seizures, stroke, behavioral problems, and coma. The fever group included all patients with suspected sepsis or fever. Theobstetric/gynecologic group included those patients with the diagnosis of vaginal bleeding, infants delivered in the field or impending delivery, or abortion. The other group included diagnoses that did not fit in the aforementioned categories and unknown diagnoses.