Methods: Smokers (n=6,451) visiting the American Cancer Society's internet site offering cessation assistance were, after providing consent and meeting eligibility criteria, randomized to receive access to a static internet site with quitting advice or to one of five interactive sites provided by the following cooperating research partners: Centre for Addiction and Mental Health, Oregon Center for Applied Science, QuitNet, ProChange, and SmokeClinic.

Results: Follow-up surveys were conducted via online survey with email prompts and telephone calls to assess quitting success at 4, 7, and 13 months following registration. At the 13-month follow-up 38% provided follow-up data. Thirteen-month results showed no significant overall difference in cessation rates among participants assigned to the interactive or static sites. There were however large differences in the utilization of the five interactive sites. When sites were grouped by level of use, there was a significantly higher reported 13-month cessation rate among participants assigned to the more highly utilized sites than among those assigned to the less utilized sites (12.5% vs. 10.6% of all randomized participants, 32.1% vs. 27.9% of followed participants).

Conclusions: Thirteen-month findings indicated that interactive internet sites yielding high levels of utilization can increase quitting success among smokers seeking assistance via the internet. Four and seven- month results will also be discussed at this meeting.