Desire to quit smoking spreads among social groups, study finds

Research suggests strong influence from close peers

NEW YORK - For years, smokers have been exhorted to take the initiative and quit - use a nicotine patch, chew nicotine gum, take a prescription medication that can help, call a help line, or just say no. But a new study finds that stopping is seldom an individual decision.

Smokers tend to quit in groups, the study finds, which means smoking cessation programs should work best if they focus on groups instead of individuals. It also means that people might help many more than just themselves by quitting - stopping can have a ripple effect prompting an entire social network to break the habit.

The study, by Dr. Nicholas Christakis of Harvard Medical School and James Fowler of the University of California in San Diego, followed thousands of smokers and nonsmokers for 32 years, from 1971 until 2003, studying them as part of a large network of relatives, coworkers, neighbors, friends, and friends of friends.

It was a time when the percentage of adult smokers in the United States fell from 45 percent to 21 percent. As the investigators watched the smokers and their social networks, they saw what they said was a striking effect - smokers had formed social clusters and, as the years went by, entire clusters of smokers were stopping en masse. And so were clusters of clusters that were only loosely connected.

Christakis described watching the vanishing clusters as like lying on your back in a field, looking up at stars that were burning out. "It's not like one little star turning off at a time," he said. "Whole constellations are blinking off at once."

As cluster after cluster of smokers disappeared, those that remained were pushed to the margins of society, isolated, with fewer friends and fewer social connections.

"Smokers used to be the center of the party, but now they've become wallflowers," Fowler said.

"We've known smoking was bad for your physical health," he said. "But this shows it also is bad for your social health." Smokers, he said, "are likely to drive friends away."

Their paper is to be published today in The New England Journal of Medicine.

"There is an essential public health message," said Richard Suzman, director of the office of behavioral and social research at the National Institute on Aging, which financed the study. "Obviously, people have to take responsibility for their behavior," he said. But a social environment, he added, "can just overpower free will." With smoking, that can be a good thing, researchers noted.

But there also is a sad side. As Dr. Steven Schroeder of the University of California in San Francisco pointed out in an editorial accompanying the paper, "a risk of the marginalization of smoking is that it further isolates the group of people with the highest rate of smoking - persons with mental illness, problems with substance abuse, or both." These are people, he notes, who already suffer from being stigmatized.

It is not clear how to resolve that problem, Fowler said. "What we are seeing is that there is a fundamental tradeoff to having a campaign to really change people's behavior," he said.

The study also looked at smoking initiation but, because many more adults were stopping smoking than starting during the years of the study, its main focus was on smoking cessation. Still, Christakis said, smoking initiation followed the same patterns as smoking cessation - people started to smoke in groups and they stopped in groups.

But such studies of social networks and behavior like smoking are extremely difficult because what is needed is detailed information on people's behavior and the behavior of their family, their relatives, their neighbors and co-workers, their friends and their friends of friends. Christakis and Fowler discovered one data set that had what they needed but, they and others say, there may not be any others.

The data were from the federal Framingham Heart Study. It was initiated after World War II to follow the population of Framingham, Mass., to understand the causes and consequences of heart disease.

The researchers focused on 5,124 people in the Framingham study who had 53,228 friends, relatives, and neighbors as part of their social networks.

They noticed that, on average, smokers clustered in groups of three. Over the years, as fewer and fewer Americans smoked, the number of clusters declined but the clusters that remained stayed the same size, which meant that smokers were stopping in groups.

Education also played a role. Those with more education were more highly influenced by their friends and their friends were more likely to influence them.