Background: Internet programs for smoking cessation are widely available but few controlled studies demonstrate long-term efficacy.
Purpose: To determine the 13-month effectiveness of an Internet program presenting a set sequence of interactive steps, and the role of depressed affect.
Methods: In a randomized controlled trial sponsored by the American Cancer Society, a treatment condition (n = 1,106) was compared to a control site (n = 1,047).
Results: More treatment condition participants were abstinent (30-day point prevalence) than control site participants (12.9% vs. 10.1%, p < .05) at 13 months. This effect was greater among participants not reporting depressed affect (15.0% vs. 10.1%, p < .01). Among smokers who reported depressed affect, there was no difference in abstinence between the treatment and control conditions.
Conclusions: Data support the long-term efficacy of an Internet intervention for cessation modeled on a structured, in-person treatment approach, especially for participants not experiencing daily depressed affect.