Family doctors routinely ask their patients whether they smoke, watch their diet, remember to fasten their seat belt. Now, in an essay in The New England Journal of Medicine, a doctor suggests adding a question to that litany: Do you drive while texting or talking on a cellphone?

The physician, Dr. Amy N. Ship, a primary care doctor and assistant professor at the Harvard Clinical and Translational Science Center, called on her colleagues to initiate these discussions, saying they are well worth the time and effort.

“This is such an easy way to keep people healthy — it’s prevention, and it’s such low-lying fruit,” Dr. Ship said in an interview. “As physicians, we have an opportunity to counsel patients. It’s an enormous power, and we should take advantage of it.”

In her essay, Dr. Ship says she often initiates the discussion by asking about texting while driving, using that as an opening to mention that talking on the phone actually causes more accidents. When patients ask why a phone conversation should be any more dangerous than talking to a passenger in the car, she said, she talks about the difficulties of multitasking.

“When patients aren’t convinced,” she said, “I ask them, ‘How would you feel if your surgeon talked on the phone — hands free, of course — while operating?’ ”