Randomized trial of a secondhand smoke exposure reduction intervention among hospital-based pregnant women

Objective: This study sought to assess the effectiveness of a secondhand tobacco smoke (SHS) prevention program based on an expanded Health Belief Model (HBM) incorporating self-efficacy among pregnant women in a hospital setting in Taiwan. Methodology: This study utilized a two-group longitudinal randomized controlled trial design. Participants in the intervention group (n = 50) enrolled in a SHS prevention program based on the HBM, while participants in the comparison group (n = 50) received standard government-mandated counseling care. Both groups were given questionnaires as a pre-test, two weeks into the intervention, and one month following the conclusion of the intervention. The questionnaire and intervention were developed based on the understanding gained through a series of in-depth interviews and a focus-group conducted among pregnant women. Exhaled carbon monoxide was also measured and used as a proxy for SHS exposure. Results: Intervention group scores were all significantly higher than comparison group scores (p < 0.001), indicating a significant increase in knowledge, HBM scores, cues to action, self-efficacy, preventative behaviors, and a significant decrease in smoking exposure. These differences remained significant at the one-month follow-up assessment (p < 0.001). Conclusions: These results should encourage health professionals to educate pregnant women regarding the harms of SHS while both empowering and equipping them with the tools to confront their family members and effectively reduce their SHS exposure while promoting smoke-free social norms.