Abstract
Background: The Iowa Infant Feeding Attitude Scale (IIFAS) is widely used to assess breastfeeding attitudes, which are linked to positive breastfeeding practices. However, its psychometric validation in Southeast Asian healthcare students remains limited. Objectives: To investigate the reliability and validity of the IIFAS among Vietnamese healthcare students. Methods: A cross-sectional study was conducted at three medical universities in Vietnam. A total of 542 healthcare students, including medical, nursing, and midwifery students, participated. The students completed the Iowa Infant Feeding Attitude Scale, Breastfeeding Knowledge Scale, and Generalized Anxiety Disorder Scale. The reliability was assessed through the internal consistency and test-retest reliability. The construct validity was tested using exploratory and confirmatory factor analysis. The divergent validity, convergent validity, and known-group comparison were also assessed. Results: The IIFAS showed an excellent internal consistency (Cronbach's α = 0.94) and test-retest reliability (intraclass correlation = 0.91). A two-factor structure of the Vietnamese IIFAS was identified using exploratory and confirmatory factor analysis with satisfactory fit indices (χ(2)/df = 1.318, comparative fit index = 0.985, Tucker-Lewis Index = 0.983, and Root Mean Square Error of Approximation = 0.034). Breastfeeding attitudes positively correlated with breastfeeding knowledge (r = 0.74, p < 0.001) and negatively correlated with anxiety symptoms (r = -0.13, p = 0.04). Students who were older, in a higher academic year, and majoring in medicine had significantly higher breastfeeding attitude scores (ps < 0.05). Conclusions: The Vietnamese version of the IIFAS demonstrates excellent reliability and validity, making it a robust tool for assessing breastfeeding attitudes and informing tailored educational programs among healthcare students.