Cigarette use among high school students hit an all-time low, but e-cigarette use has more than replaced it, according to the latest data from the CDC's 2015 National Youth Risk Behavior Surveillance survey.

While only 11% of U.S. high school students reported smoking cigarettes in the previous 30 days -- the lowest rate since the agency started keeping track in 1991, when it was 28% -- almost a quarter (24%) of high school students reported using e-cigarettes in the last 30 days, reported Laura Kann, PhD, of the CDC, and colleagues, writing in a special edition of the Morbidity and Mortality Weekly Report.

This is the first time the survey has measured e-cigarette use in the survey.

Overall, 31% of adolescents reported recent use of tobacco products in 2015, including cigarettes, cigars, and smokeless tobacco as well as vapor devices -- up from 27.5% in 2003, the year before e-cigarettes were first introduced.

"Current cigarette smoking is at an all-time low, which is great news. However, it's troubling to see that students are engaging in new risk behaviors, such as using e-cigarettes," CDC director Tom Frieden, MD, said in a statement. "We must continue to invest in programs that help reduce all forms of tobacco use, including e-cigarettes, among youth."

Other Risk Behaviors

Prescription drug use among students decreased slightly (from 20% in 2009 to 17% in 2015), but Stephanie Zaza, MD, director of CDC's division of adolescent and school health, said that number was still concerning: "Seventeen percent of high school students think it's OK to take drugs without a prescription. Other than alcohol and marijuana use, prescription drugs are the most frequent form of drug-taking among these kids," she said in a telephone briefing.

Risky sexual behaviors among these students also continued to decline, with 30% of students reporting being sexually active (down from 38% in 1991). However, condom use has declined from 2003 (63% to 57%), and the proportion of students who reported being tested for HIV also ticked down (now 10%, versus 13% in 2013).

"Adolescence is a time when healthy or risky behaviors are established, and these can last a lifetime," said Zaza. "In each topic, we are encouraged to see high school students making better choices, but we also continue to face challenges."

Dietary and sedentary-related behaviors showed mixed results, with a quarter of students drinking soda one or more times a day (down from 27% in 2013). But Zaza characterized students' sedentary-related behaviors as "problematic," as almost half (42%) of teenagers reported spending three or more hours a day playing video or computer games or using a computer for nonschool-related work. This is a significant increase from 2003, when it was 22%.

Examining interpersonal violence among teenagers, there was also good news and bad news: While the number of students who reported being in a physical fight was nearly halved (23% compared with 42% in 1991), 20% of students reported being bullied on school property.

The National Youth Risk Behavior Surveillance survey is conducted every 2 years, and examines 15,000 U.S. high school students. Overall, Zaza said that these results show that clearly fewer high school students are engaging in risky health behaviors, but there is still more work to be done. She encouraged public health officials and community members to continue to use evidence-based interventions to help to stem these types of behaviors.

"There is no single solution to reduce health risk behaviors among high school students, so we can all collaborate using interventions based on the best science available," she said.