Aims To examine if menstrual phase affects relapse in women attempting to quit smoking.
Design An intent-to-treat randomized smoking cessation trial where women were assigned to quit smoking in either the follicular (F) or luteal (L) menstrual phase and were followed for up to 26 weeks. They were assessed for relapse by days to relapse and relapse phase to determine if those who begin a quit attempt during the F phase were more successful than those who begin during the L phase.
Setting Tobacco Use Research Center, University of Minnesota, Minneapolis, Minnesota.
Participants A total of 202 women.
Measurements Latency to relapse from continuous and prolonged abstinence, point prevalence, phase of relapse, first slip within the first 3 and 5 days post-quit date, subject completion rates and symptomatology (i.e. withdrawal and craving).
Findings The mean days to relapse from continuous abstinence and relapse from prolonged abstinence for the F group were 13.9 and 20.6 days, respectively, and 21.5 and 39.2 days, respectively, for the L group. Using point prevalence analysis at 14 days, 84% of the F group had relapsed compared with 65% of the L group [χ2 = 10.024, P = 0.002; odds ratio (OR) = 2.871, 95% confidence interval (CI), 1.474–5.590]. At 30 days, 86% of the F group relapsed, compared with 66% of the L group (χ2 = 11.076, P = 0.001; OR = 3.178, 95% CI, 1.594–6.334).
Conclusion Women attempting to quit smoking in the F phase had less favorable outcomes than those attempting to quit in the L phase. This could relate to ovarian hormones, which may play a role in smoking cessation for women.