An automated external defibrillator automatically determines the type of patient to which it is attached based on patient-specific information entered by the user. The defibrillator includes electrodes that are adapted for placement on a patient, a pulse generator connected to the electrodes, and processing circuitry that controls the defibrillation pulse delivery from the pulse generator. The automated external defibrillator causes a defibrillation pulse to be delivered to the patient in accordance with the determined patient type. A user interface having a user input connected to the processing circuitry enables the user of the defibrillator to enter patient-specific information. The user may enter the patient-specific information by interacting with the user input during a time period in relation to a prompt from the defibrillator. In another aspect, data pertaining to identification of the type of patient connected to the electrodes may be recorded with event data in a memory.