PRELIMINARY PSYCHOMETRIC EVALUATION OF A BILINGUAL QUESTIONNAIRE ASSESSING DETERMINANTS OF COVID-19 VACCINE BOOSTER HESITANCY AMONG MALAYSIANS: AN EXPLORATORY STUDY

Abstract

COVID-19 vaccine booster hesitancy (CVBH) remains a significant public health concern, yet validated instruments tailored to the Malaysian context are limited.  The study adapted a previously validated instrument with modifications to reflect the booster vaccination context.  This was used in a preliminary psychometric evaluation of the bilingual (English-Bahasa Melayu) questionnaire to assess knowledge and perceptions related to CVBH.  A cross-sectional validation study was conducted among 141 Malaysian adults ≥18 years of age, 78% female and 94% Malay ethnicity.  The knowledge domain was evaluated using a two-parameter logistic item response theory (IRT) model, while the perception domain was assessed using an exploratory factor analysis (EFA) with principal component extraction and varimax rotation.  The questionnaire demonstrated strong average item content (knowledge = 0.92, perception = 0.89) and face validity (knowledge = 0.89, perception = 1.00) scores.  IRT analysis indicated acceptable item difficulty and discrimination parameters, although two items showed extreme discrimination due to limited response variability.  EFA supported a five-factor structure covering 62% of the total variance.  The study provides preliminary evidence supporting the validity and reliability of a bilingual instrument for assessing CVBH parameters in the Malaysian population.  Further validation using confirmatory approaches among a larger cohort of a more diverse demographic population is recommended to establish an improved model fit and generalizability.