Abstract
OBJECTIVES: This paper aims to evaluate the performance of a questionnaire about pregnant Brazilian women's attitudes towards and knowledge of COVID-19 vaccines. The findings highlight the importance of tailored psychometric instruments to accurately capture the unique concerns and cultural context of this population. Such tools are essential for informing policymakers in developing targeted strategies and campaigns to increase COVID-19 vaccine uptake during pregnancy. METHODS: A cross-sectional survey of COVID-19 vaccine knowledge, attitudes, and practices took place among pregnant women in two hospitals in southeast Brazil, between August and December 2023. We used a structured approach to evaluate 27 survey questions related to attitudes toward COVID-19 vaccines and sources of knowledge, answered on a four-point Likert scale. We used Cronbach's alpha, in addition to factorial analysis, to measure sampling adequacy (Kaiser-Meyer-Olkin, KMO). Pearson's correlation coefficient was used to evaluate the content and correlations between both groups of the instrument among women who had been vaccinated in pregnancy and those who had vaccine hesitancy. RESULTS: The 27-item questionnaire demonstrated high reliability (Cronbach`s alpha = 0.912), with potential redundancy identified in seven questions. Removing these questions increased the Cronbach`s alpha to 0.921 for the 20-item questionnaire. The 20-item scale showed distinct score distributions between vaccine-hesitant and vaccinated pregnant women, with significant differences (p < 0.001). Confirmatory factor analysis of the 20-item scale yielded a high KM0 value (0.908) and was significant using Bartlett`s test (p < 0.001), grouping questions into five factors related to vaccine safety, impact on the baby, influence of social circles, trust in information sources and recommendations by authorities. The ROC curve analysis showed the 27-item scale and 20-item scale had an AUC of 0.714 and 0.731, respectively. CONCLUSION: The 20-item instrument demonstrated strong reliability and internal consistency, making it a valuable tool for assessing COVID-19 vaccine attitudes among pregnant women in Brazil. Its concise format may enable easier administration without compromising accuracy. Further validation could enhance its role in informing vaccination strategies and improving maternal and neonatal outcomes.