Reliability and validity of the German version of the Iowa infant feeding attitude scale (IIFAS-G) and relations to breastfeeding duration and feeding method

BACKGROUND: Public health initiatives (e.g., the Baby Friendly Hospital Initiative) have led to an increase in breastfeeding rates worldwide. However, as (exclusive) breastfeeding duration is still below WHO recommendations, it is crucial to understand the factors that influence decisions on breastfeeding practice. Modifiable psychological factors such as intention to breastfeed have therefore become targets of recent interventions. As the intention to breastfeed is among the strongest predictors of breastfeeding duration, reliable tools for measuring the intention to breastfeed are needed. The Iowa Infant Feeding Attitude Scale (IIFAS) measures attitudes towards infant feeding and is used in various languages and across different cultural contexts. However, there has been no German version of the IIFAS (IIFAS-G) so far. The aim of this study was to investigate reliability, validity, and associations of the IIFAS-G with feeding method and breastfeeding duration. METHODS: Between August and November 2022, a total of 353 mothers (M$_{age}$ = 35 years, SD$_{age}$ = 4.2 years) of singleton infants (47.3% female (1 undetermined), M$_{age}$ = 10.8 months, SD$_{age}$ = 4.7 months, age range: 3-547 days; 90.4% living in Switzerland) participated in an online survey. The IIFAS-G was administered as a part of a larger study on early child development and infant feeding method. RESULTS: The translated IIFAS-G showed unsatisfactory model fit for the two factor 17-item solution. Four items showed low factor loadings. After item reduction, a 13-item two factor solution showed satisfactory model fit (CFI = 0.92, TLI = 0.90, RMSEA = 0.07) and high internal consistency (Cronbach's α = 0.85). The IIFAS-G score was higher for mothers who exclusively breastfed their infants compared to mothers who additionally or exclusively fed infant formula. Moreover, mothers with higher IIFAS-G scores were less likely to stop breastfeeding their child over the course of 1.5years (HR = 0.87). CONCLUSION: A shorter two-factor IIFAS-G is proposed to investigate attitudes towards breastfeeding and formula feeding in German-speaking mothers.