Efficacy of a Web-Based Intervention to Increase Uptake of Maternal Vaccines: An RCT.

Introduction: Tetanus, diphtheria, and acellular pertussis (Tdap) and influenza vaccines are recommended for pregnant women in each pregnancy, yet uptake is suboptimal. This study tested the efficacy of an online vaccine resource in increasing uptake of Tdap and influenza vaccines among pregnant women.

Study Design: RCT.

Setting/participants: This study was conducted among women in the third trimester of pregnancy in an integrated healthcare system in Colorado in September 2013-July 2016, with data analysis in 2017-2018.

Intervention: Women were randomly assigned to 1 of 3 arms: website with vaccine information and interactive social media components, website with vaccine information only, or usual care. Participants in the website with vaccine information and interactive social media components and website with vaccine information only arms had access to the same base vaccine content. The website with vaccine information and interactive social media components also included a blog, discussion forum, and "Ask a Question" portal.

Main Outcome Measures: Tdap and influenza vaccination. These outcomes were analyzed separately.

Results: For influenza (n=289), women in both the website with vaccine information and interactive social media components (OR=2.19, 95% CI=1.06, 4.53) and website with vaccine information only (OR=2.20, 95% CI=1.03, 4.69) arms had higher vaccine uptake than the usual care arm. The proportions of women receiving the influenza vaccine were 57%, 55%, and 36% in the website with vaccine information and interactive social media components, website with vaccine information only, and usual care arms, respectively. For Tdap (n=173), there were no significant differences in vaccine uptake between study arms. The proportions of women receiving Tdap were 71%, 69%, and 68% in the website with vaccine information and interactive social media components, website with vaccine information only, and usual care arms, respectively.

Conclusions: Web-based vaccination information sent to pregnant women can positively influence maternal influenza vaccine uptake. Because of potential scalability, the impact of robust vaccination information websites should be studied in other settings.

Trial Registration: This study is registered at www.clinicaltrials.gov NCT01873040.