Online social networks designed to help smokers kick the tobacco habit are effective, especially if users are active participants, according to a new study from the University of Iowa and the Truth Initiative, a nonprofit anti-tobacco organization.

The study examined the tobacco use of more than 2,600 smokers who participated in BecomeAnEX.org, Truth Initiative’s online smoking cessation community designed in collaboration with the Mayo Clinic. The study found that 21 percent of those classified as active users after their first week in the community reported that they quit smoking three months later. Those who were less active in the community were less likely to quit.

Kang Zhao, assistant professor of management sciences in the UI Tippie College of Business and the study’s co-author, says the results show that online interactions can predict offline behavior.

“How central you become in the online social network after the first week is a good indicator of whether you will quit smoking,” says Zhao. “This is the first study to look at smokers’ behaviors in an online community over time and to report a prospective relationship between social network involvement and quitting smoking.”

The BecomeAnEX website enables members to share information and support through blogs, forums, and messages. Although the site is focused on smoking cessation, users can post on any topic. More than 800,000 users have registered since the site launched in 2008, resulting in a large, active community of current and former tobacco users supporting each other.

Funded by the National Cancer Institute, the study constructed a large-scale social network based on users’ posting habits. Zhao says a key finding was that increasing integration into the social network was a significant predictor of subsequent abstinence. Three months after joining the BecomeAnEX social network, users who stayed involved on the site were more likely to have quit smoking when researchers contacted them to assess their smoking status.

After three months, 21 percent of active users—or those who actively contributed content in the community—quit smoking; 11 percent of passive users—those who only read others’ posts—quit smoking; and only 8 percent of study participants that never visited quit smoking.

The study did not examine why greater community involvement had such a positive effect on smoking cessation. Researchers speculate it may be because of powerful social network influences.

“Spending time with others who are actively engaged in quitting smoking in a place where being a nonsmoker is supported and encouraged gives smokers the practical advice and support they need to stay with a difficult behavior change,” says Amanda Graham, senior vice president, Innovations, of Truth Initiative and lead author. “We know that quitting tobacco can be extremely difficult. These results demonstrate what we hear from tobacco users, which is that online social connections and relationships can make a real difference.”

The paper, “A prospective examination of online social network dynamics and smoking cessation,” was recently published in the journal PLOS One. It was co-authored by Amy Cohn, Sarah Cha, Michael Amato, and Jennifer Pearson of Truth Initiative; George Papandonatos of Brown University; Bahar Erar of Johns Hopkins University; and Xi Wang of the University of Iowa and the Central University of Finance and Economics, China.