Teens today, whether through media, friends or some other means, are constantly being exposed to sex. Missing from the conversation, however, is an important voice: doctors.

According to a study published in JAMA Pediatrics, less than two-thirds of doctors and teenage patients talk about sex, sexuality or dating during annual check-ups. Even when those discussions do take place, the researchers found they last on average less than a minute.

"It's hard for physicians to treat adolescents and help them make healthy choices about sex if they don't have these conversations," said lead author Stewart Alexander, associate professor of medicine at Duke. "For teens who are trying to understand sex and sexuality, not talking about sex could have huge implications."

In the past, studies regarding discussions of sex during doctors' visits relied on reports by teens or physicians after visits took place. Alexander and his colleagues, in contrast, gathered audio recordings of annual visits for 253 adolescents ranging in age from 12-17. A total of 11 North Carolina clinics were included in the study.

The researchers then listened to the recordings for any mention of sexual activity, sexuality or dating, finding that while physicians brought up sex in 65 percent of visits, those discussions lasted on average just 36 seconds.

Not once did the patient initiate a conversation on sex - reinforcing the need, the researchers said, for doctors to be the ones to bring it up.

"We saw that physicians spent an average of 22.4 minutes in the exam room with their patients. Even when discussions about sex occurred, less than 3 percent of the visit was devoted to topics related to sex," Alexander said. "This limited exchange is likely inadequate to meet the sexual health prevention needs of teens."

Females were far more likely to spend time talking about sex, according to the study, suggesting their male counterparts may be missing out to an even greater degree in these visits.

"The implication for males is troublesome because as they get older, they become less likely to routinely see physicians outside of checkups or sports physicals," Alexander said. "Thus, the annual visits become essential and are perhaps the only opportunity for physicians to address the sexual behaviors of adolescent boys."