Smokers who want to kick the habit have a number of tools to help them succeed. They can ask their doctor about medications to control nicotine addiction, turn to a telephone quitline for support and counseling, and even go online. But while many online cessation services are available, not much information exists to help smokers choose one that is likely to work.

An Internet-based clinical trial sponsored by the American Cancer Society may help. ACS is now enrolling smokers in QuitLink, a study of 6 different online quitting services.

"We know there are a lot of smokers out there who really want to quit, and it's difficult," said Joanne Pike, MA, LPC, director of the ACS Quitline, a telephone-based cessation service. "[This study] will give us answers on how best to help smokers quit using online resources."

The study will include 6,000 English-speaking smokers over age 18. Participants will be randomly assigned to one of the following programs: QuitNet, SmokeClinic, ProChange, the Oregon Center for Applied Science, Centre for Addiction and Mental Health VCC, or an ACS program.

Each has a different approach to smoking cessation. Some, for instance, have a heavy focus on motivating and preparing the smoker for the eventual quit day, while others rely more on providing educational materials or support from counselors and other smokers.

Though some of the programs charge a fee, study participants will be given free enrollment if assigned to a service that normally charges. (ACS quitting resources are free for everyone, whether they're part of the study or not.) Their progress will be checked 3, 6, and 12 months after enrolling. The study is the largest Web-based trial of smoking cessation programs ever conducted in the United States.

"Part of the reason that we're interested in doing this and committing resources to it is that so far, we don't have a good randomized trial that looks at how effective Web services are, and there are lots of people who believe in them," said Vance Rabius, PhD, MA, evaluation manager of the ACS Quitline.

Several studies have shown that telephone counseling can improve a smoker's chance of quitting successfully. In one ACS study conducted in 2000, smokers were twice as likely to stay quit after a year if they had access to counseling (Tobacco Control 2004; Vol. 13, No. 1:85-86).

It remains to be seen if online cessation services will have the same success. One problem researchers often encounter, Rabius said, is tracking down participants after they've finished an online program to find out if they're still off cigarettes. Follow-up is likely to be a challenge with the ACS study as well, he admitted.

But the information gleaned could help some of the 46 million adult smokers in the US quit.

"If [online cessation] is as successful as telephone counseling, that would be very nice, because we think it serves a different population and we know telephone counseling doesn't reach everyone," Rabius said. "And, once an online program is set up, it's relatively inexpensive to maintain and can reach a very large number of constituents."