(Reuters Health) - More than half of U.S. teens overestimate how often their peers smoke hookah, and a new study suggests this makes them more than nine times more likely to try it themselves.

“Adolescence is a critical developmental stage when youth are under pressure to fit in socially,” said lead study author Dr. Israel Agaku, a scientist at the Office on Smoking and Health at the U.S. Centers for Disease Control and Prevention (CDC) in Atlanta.

“Peer pressure, along with frequent exposure to pro-tobacco advertising, may lead youth to believe that hookah smoking is far more common than it actually is,” Agaku said by email. “The likelihood of youth smoking hookah may increase if they believe that `everyone else is doing it’ even if that perception is inaccurate.”

The vast majority of American teens have never tried hookah, a water pipe used to smoke flavored or sweetened tobacco.

Although many users think it is less harmful, hookah smoking has many of the same health risks as cigarette smoking, according to the CDC.

Overall, only about 11 percent of students in sixth through 12th grade have tried it, Agaku’s team found.

But three in five teens overestimate how many of their classmates smoke hookah, they report in Pediatrics.

Youths’ perception of hookah popularity among their peers was higher than actual usage rates by as much as 10-fold in ninth grade and by at least five-fold in twelfth grade.

For the study, researchers examined survey data on tobacco use collected in 2016 from a nationally representative sample of 20,675 teens.

Among the minority of participants who had tried hookah at least once, 66 percent were former users. Another 26 percent said they currently used hookah on occasion, and about 8 percent said they currently smoked hookah on a regular basis.

The biggest predictor of hookah use was living with a hookah smoker, the study found. Students in this situation were more than 20 times more like to use hookah than youth without a hookah smoker at home.

Menthol cigarette use was a very close second. Teens who currently smoked menthol cigarettes were more than 19 times more likely to use hookah than adolescents who didn’t. The increased risk of hookah use was also more than 17 times greater for youth who used other types of flavored tobacco products.

Most teen hookah use doesn’t happen at hookah bars and restaurants that are popular with college students and young adults.

In this study, 48 percent of teens said they used hookah at a friend’s house; 31 percent said they tried it in their own home; and 21 percent smoked at a relative’s house.

This suggests that efforts designed to restrict hookah use by teens in pubic venues may be insufficient to address the problem, said Dr. Benjamin Chaffee, a tobacco researcher at the University of California, San Francisco who wasn’t involved in the study.

“Flavor restrictions and limiting hookah venues to age 21 and above are important for preventing youth use, but the high prevalence of hookah smoking at home implies a strong need to communicate with youth, parents, and other family members about the harms of hookah smoking,” Chaffee added.

The study wasn’t a controlled experiment designed to prove whether or how teens’ social lives might directly impact their hookah use. Another limitation of the study is that it only includes youth enrolled in school.

Even so, the findings mirror other research suggesting that teens overestimate how much their peers drink and smoke, and that these misperceptions can influence behavior, said Thomas Wills, director of the Cancer Prevention in the Pacific Program at the University of Hawaii Cancer Center in Honolulu.

“It is a general tendency among adolescents to assume that problem behaviors are more prevalent than they actually are, partly because teens are more likely to discuss use than abstention, and usage is likely to be more visible and impactful than abstention,” Wills, who wasn’t involved in the study, said by email.

“Also, abstainers may feel constrained about expressing their views because they feel it’s not cool,” Wills added.

SOURCE: bit.ly/2tVf72M Pediatrics, online July 2, 2018.