At a routine appointment a few days after my 40th birthday, my gynecologist gave me a prescription for a mammogram. There was no discussion, no explanation. Just a slip of paper, handed to me without a word as I left the examination room. When I asked the doctor what she’d just given me, she told me it was an order for a mammogram. I could call the number to schedule an appointment.

“Wait—why should I get a mammogram?” I asked.

“Because it could save your life.” Her voice conveyed a note of impatience.