Reliability and Validity of the Japanese Version of the Iowa Infant Feeding Attitude Scale: A Longitudinal Study

Background: The 17-item Iowa Infant Feeding Attitude Scale (IIFAS) has shown good reliability and validity to measure attitudes toward infant feeding in various countries. It is also known to be associated with breastfeeding intention and exclusivity. However, the IIFAS has not been psychometrically tested among Japanese women.

Objective: This study aimed to develop the Japanese version of the IIFAS (IIFAS-J) and assess its reliability and validity.

Methods: This longitudinal study was conducted with 781 women at 4 hospitals in Japan. The translated IIFAS was administered to participants during their third trimester. Infant feeding status was self-reported at 4 and 12 weeks postpartum using follow-up questionnaires. The predictive validity was determined by examining the association between the IIFAS-J score during pregnancy and infant feeding status at 4 and 12 weeks postpartum.

Results: One item was removed after a principal components analysis. Therefore, the IIFAS-J consisted of 16 items. Cronbach's alpha of the IIFAS-J was 0.66. A higher IIFAS-J score during the third trimester was associated with a higher postdischarge exclusive breastfeeding rate at 4 weeks postpartum (B = 0.05; adjusted odds ratio = 1.05; 95% confidence interval, 1.01-1.10).

Conclusion: The 16-item Japanese version of the IIFAS is a reliable and valid scale for measuring maternal infant-feeding attitudes during pregnancy.