ABSTRACT
BACKGROUND: Beliefs of an individual about health conditions can play an important role in contributing to their behavior concerning good and bad health practices. The aim of this study was to develop and assess a set of vaccination belief scales in relation to COVID-19 vaccines. METHODS: A cross-sectional study was conducted between July 2020 and January 2021 using a systematic random sampling of 425 adult outpatients at two hospitals in Ho Chi Minh City, Vietnam. An instrument was designed based on the dimensional structure and wording of the health belief model (HBM), which was followed by the assessment of the instrument's internal consistency and the construct validity. RESULTS: The 15-item instrument showed the content validity index (CVI) of scales reached a value of 1.0. Exploratory factor analysis was performed on the first sample (n = 170) and extracted 12 out of 15 draft items in a four-factor model (threat of disease, perceived benefits, perceived barriers, and cues to action) that accounted for 68.3% of the total variance. Cronbach's alpha coefficient of 0.765 showed as satisfactory. Following this, the confirmatory factor analysis in the remaining sample (n = 255) found a good fit between a four-factor model and a theoretical model of HBM with acceptable values of fit indices. CONCLUSION: Beliefs scales for COVID-19 vaccination have been determined to be valid and reliable. They can be a helpful instrument for health educators to use for assessing immunization beliefs of individuals and the public where there is the need to implement new vaccines, such as the COVID-19 vaccine, before they are used more widely across the community.