Effects of a Comic Booklet Intervention Aimed at Preventing Second-Hand Smoke Exposure for Pregnant Women in Indonesia: A Randomised Controlled Trial

Second-hand smoke (SHS) has adverse effects for pregnant women and foetuses. This controlled and randomized clinical trial evaluated the efficacy of a comic booklet intervention in promoting SHS avoidance among pregnant women and appropriate smoking behaviours among their male partners. We allocated 140 couples to the experimental group (EG), who received the comic booklet and a reminder sticker, and 146 couples to the control group (CG), who received usual care. The primary outcomes were women's self-reported SHS exposure and their male partners' smoking behaviours. Secondary outcomes included knowledge and awareness of SHS. Independent -tests revealed that three months post-intervention, more male partners in the EG had appropriate self-reported smoking behaviours with a small effect size (Cohen's d = 0.35, 95% CI [0.08, 0.62], -value = 0.01). Significantly more pregnant women in the EG recognised their partners' appropriate smoking behaviours with a nearly middle effect size (Cohen's d = 0.43, 95% CI [0.16, 0.70], -value ≤ 0.01). Cues to action showed a significant difference between groups with a small effect size (Cohen's d = 0.36, 95% CI [0.09, 0.63], -value = 0.01), as evaluated by male partners. These findings suggest that the comic booklet intervention might be effective against SHS exposure by providing several cues to action through knowledge and awareness of SHS.