"It's a warm afternoon in Miami, and 35-year-old Emanuel Vega has come to Baptist Health Primary Care for a physical exam. Dr. Mark Caruso shakes his hand with a welcoming smile."

"Vega, a strapping man with a thick black beard, is feeling good, but he came to see the doctor today because his wife thought he should. She even made the appointment. It is free to him under his insurance policy with no copay, as most preventive care is under the Affordable Care Act."

"Vega is one of more than 44 million Americans who is taking part in a medical ritual — visiting the doctor for an annual physical exam. But there's little evidence that these visits actually do any good for healthy adults."