Promoting Tdap immunization in pregnancy: Associations between maternal perceptions and vaccination rates

Abstract

Objective: Tdap vaccine uptake among US pregnant women is low despite current recommendations. This study evaluated if a Tdap vaccine information statement (VIS) affected overall perception, vaccination intention, and components of a health behavior model associated with Tdap vaccination rates.

Methods: A randomized, prospective study was conducted among pregnant women receiving care at two women's clinics in May-August 2014. Verbally consented participants were randomized to receive either the standard CDC Tdap VIS (sVIS) or a modified version (mVIS) before completing the first multi-part survey (T1). After T1, participants read their assigned VIS then completed the second part (T2). A 2015 chart review identified vaccinated participants. A health behavior model was hypothesized using the Reasoned Action Approach and Health Belief Model. Logistic regression, path analysis, and chi-square tests were used in the analysis.

Results: 279 surveys were analyzed. Average age of the participants was 26.4 years (SD=5.7) with average gestational age of 25.9 weeks (SD=9.2). 13% self-reported receiving Tdap vaccine prior to the survey. Overall perception scores significantly increased (3.1-3.4, p<0.001) after VIS review. A chart review showed that 131 (47%) received the vaccine post study. There was no significant difference in vaccination rates between the sVIS and mVIS groups (45% vs. 49%). Perceived benefits (B=0.315) and self-efficacy (B=0.197) were positively associated with the overall perception (T1), while perceived barriers (B=-0.191) were negatively associated with the overall perception (T1). Social norms (B=0.230), self-efficacy (B=0.213), and perceived benefits (B=0.117) were positively associated with vaccination intention (T1). The vaccination intention (T2) was positively associated with participants' decision to receive Tdap vaccine (B=0.223).

Conclusion: A VIS improved overall perception of the Tdap vaccine. Vaccination intention was a predictor of Tdap vaccination. It is crucial to provide information about immunization benefits to promote maternal Tdap vaccination.

Keywords: Health behaviors; Perceptions; Pertussis; Tdap VIS; Tdap maternal vaccination rates.