The effect of MI (Motivational Interviewing) in preventing smoking relapse among women at 4 months postpartum who quit smoking during the 12th to 18th week of pregnancy

Abstract

Purpose

This is to verify that if the motivational interviewing (hereafter referred as to “MI”) is applied to pregnant women who gave up smoking due to pregnancy and had maintained non-smoking for 12-18 months post-pregnancy, it maintains their non-smoking until four months after childbirth comparing with other normal care and it increases their self-confidence.

Subjects and Method

The subjects were the women who were visiting seven medical facilities regularly and gave up smoking 12-18 weeks after pregnancy. A non-randomized controlled trial was used for the survey. The support for maintaining non-smoking by MI was conducted to the intervention group of 38 subjects 22-27 weeks after pregnancy, 34-37 weeks after pregnancy, when they were discharged from hospital after delivery, a month after delivery and four months after delivery, five times in total. The comparison group of 19 subjects received no-smoking support that is normally practiced. The primary evaluation item was the measurement of CO concentration in exhalation conducted 22-27 weeks after pregnancy and four months after delivery, and the secondary evaluation items were the importance of non-smoking and self-confidence conducted 12-18 weeks after pregnancy and four months after delivery and scores were grasped. An χ² test, Wilcoxon signed rank test, and effect size were used for data analysis. This research was conducted with the approval of an Ethics Committee.

Results

Subject tracking rate of the intervention group was 55% and that of comparison group was 89%. Regarding the characteristics of the subjects, there was a significant difference in family structure only between both groups and there was no significant difference in other items. The number of subjects who were able to maintain non-smoking were 17 out of 21 from the intervention group and 12 out of 15 from the comparison group. The χ² test for independence was p=.63, so there was no significant difference. As for the differences in the scores for confidence of the intervention group and comparison group, the difference of the intervention group was significant at p=.002, and a great effect size of r=−.68 was confirmed. The difference of the comparison group was p=.06, so there was no significant difference, and a moderate effect size of r=−.48 was confirmed.

Conclusion

Conducting MI for the women who give up smoking during pregnancy was not effective in their maintaining non-smoking. Meanwhile MI showed an increased effect to their confidence in maintaining non-smoking.