inpatient is when you are admitted to hospital, like if you had heart attack and you stay in a hospital bed 1 night or more for treatment. outpatient usually is for example, a minor surgery, you go in have the surgery and go home(not to hospital) the same day. {or also, urgent care clinic, or when you go to your doctor for a checkup but this is not in a hospital so not what you're looking for} Are they looking for people who went to Emergency Room? that would be considered outpatient So a large hospital is 350+ beds?