Comparing abrupt and gradual smoking cessation: a randomized trial.

AIMS To compare abrupt and gradual smoking cessation. DESIGN AND SETTING Randomized trial and observational study, Internet, 2007-2010. PARTICIPANTS Smokers with no strong preference for abrupt or gradual quitting were randomly assigned to quitting immediately (n=472), or to gradually reducing their cigarette consumption over 2 weeks and then quit (n=502). Smokers who strongly preferred to quit abruptly were instructed to do so immediately (n=2456), those who strongly preferred gradual were instructed to reduce their cigarette consumption over 2 weeks, then quit (n=1801). Follow-up was conducted 4 weeks after target quit dates. FINDINGS Those who preferred abrupt quitting were the most motivated to quit and the most confident in their ability to quit. At follow-up, quit rates were 16% in those who preferred abrupt cessation, 7% in those who preferred gradual cessation and 9% in those who had no preference (p<0.001). In the latter group, quit rates were equal for those randomized to abrupt or gradual (9%, p=0.97). In those who expressed a strong preference for either method, there were interactions between quitting method, motivation to quit and confidence in ability to quit: those who had low levels of motivation or low levels of confidence were more likely to quit at follow-up if they preferred and used abrupt rather than gradual. CONCLUSIONS In those who had no strong preference for either method, abrupt and gradual produced similar results. Those who preferred and used the abrupt method were more likely to quit than those who preferred and used the gradual method, in particular when they had low motivation and confidence.