Quitting smoking abruptly rather than gradually leads to higher abstinence rates both at 4 weeks and 6 months, a report published online March 14 shows.

Worldwide guidelines for smoking cessation generally recommend abrupt cessation over a gradual reduction in smoking, based on data from observational studies. However a recent review of 10 randomized trials concluded that quitting “cold turkey” produces only slightly higher quit rates, said Nicola Lindson-Hawley, Ph.D., of the department of primary care health services, University of Oxford (England), and her associates.

They compared the two approaches in a noninferiority trial involving 697 adults treated at 31 primary care practices in England during a 2.5-year period. The study participants smoked at least 15 cigarettes per day and had an end-expiratory carbon monoxide concentration of at least 15 parts per million. The average age was 49 years, and the study population was evenly divided between men and women. Their mean score on the Fagerström Test for Cigarette Dependence was 6, indicating a high degree of dependence.

These participants were randomly assigned either to stop smoking abruptly on a quit date 2 weeks from baseline (355 patients) or to stop gradually, by reducing their cigarette use by half at 1 week from baseline, by half again during the second week, and completely by a quit date 2 weeks from baseline. The latter group was given a choice of three structured reduction programs to follow before the quit date, as well as nicotine patches and a choice of short-acting nicotine replacement products (gum, lozenges, nasal sprays, sublingual tablets, inhalators, or mouth sprays). The abrupt-cessation group received only the nicotine patches just before the quit day. Both groups received identical behavioral counseling, nicotine patches, and nicotine replacement products after the quit date.

The primary outcome measure, abstinence at 4 weeks, was achieved by 49% of the abrupt-cessation group, compared with only 39.2% of the gradual-cessation group (relative risk, 0.80). Thus, gradual cessation did not prove to be noninferior to abrupt cessation. The secondary outcome measure of abstinence at 6 months also was superior for the abrupt-cessation group (22%) over the gradual-cessation group (15.5%), Dr. Lindson-Hawley and her associates reported (Ann Intern Med. 2016 Mar 15. doi: 10.7326/M14-2805 ).

Most of the between-group difference was attributed to the fact that fewer participants in the gradual-cessation group actually attempted to quit on their quit date (61.4% vs. 71.0%). Relapse rates were similar between the two study groups at 4 weeks (36.2% vs. 31.0%) and at 6 months (74.8% vs. 69.1%).

“These results imply that, in clinical practice, we should encourage persons to stop smoking abruptly and not gradually,” Dr. Lindson-Hawley and her associates wrote. “However, gradual cessation programs could still be worthwhile if they increase the number of persons who try to quit or take up support and medication while trying.”

The study was supported by the British Heart Foundation, Cancer Research United Kingdom, the Economic and Social Research Council, the Medical Research Council, and the National Institute for Health Research. Dr. Lindson-Hawley reported having no relevant financial disclosures; two of her associates reported ties to Pfizer, GlaxoSmithKline, and McNeil.