The definition we typically use in medicine is anyone above the age of 65. Over that age, we begin to need significantly different resources to reduce falls, pneumonia, and hospital admissions. Geriatric emergency medicine is a newer specialty; 10 years ago, it didn't exist in the way that it does now. But the baby boomers are coming -- about a quarter of the patients who come to the Stanford ED [the Marc Andreessen and Laura Arrillaga-Andreessen Emergency Department] are over the age of 65.