Examining psychometric properties of the Iranian version of exclusive breastfeeding social support scale (EBFSS)

The exclusive breastfeeding (EBF) is undeniably proven significant in mothers' health and infants' growth and survival. Its persistence has many familial, social, and economical benefits. Social support is known to be an effective factor in EBF's success and sustainability. However, Exclusive breastfeeding social support (EBFSS) scale validity and reliability is not evaluated in Iran. This study aimed to determine the psychometric properties of EBFSS during postpartum period in Tabriz city, Iran.

It is a cross-sectional study with descriptive survey method performed between March 2021 and August 2022. Psychometric properties were determined for the Persian version of EBFSS in six stages: translation process, evaluating content validity, face validity, construct validity, discriminant validity, and reliability. A group of experts (n = 10), followed by a group of women with EBF (n = 10), evaluated the instrument's items based on content and face validities, respectively. A cross-sectional study using the multi-stage cluster random sampling method on 348 women with EBF in the first four months after delivery was conducted to determine the construct validity. The internal consistency and repeatability (test-retest on 30 women, 2 weeks apart) were used to find out the reliability.

Content validity ratio (CVR), content validity index (CVI), and impact score were 0.98, 0.98, and 3.54 for EBFSS, respectively. This indicates a good content and face validity. Exploratory factor analysis (EFA) was performed on 16 items to examine the construct validity identified emotional, instrumental, and informational factors. These factors explained 59.26% of the cumulative variance. The fit indices (CFI = 0.98، TLI = 0.95، χ²/df = 4.20، RMSEA = 0.07 and SRMSEA = 0.05) confirmed the validity of the model in a confirmatory factor analysis (CFA). The internal consistency was examined through Cronbach's alpha and McDonald's omega coefficients that were 0.90 and 0.92, respectively. Finally, Repeatability and reproducibility were found 0.97 (95% CI: 0.92 to 0.99) using Intra-class correlation. This shows an appropriate reliability of the instrument.

The research findings indicate that the Persian version of the EBFSS has appropriate psychometric properties for evaluating the social support in Iranian women with EBF. This means healthcare providers can use it for screening social support in EBF. Researchers also can use it as a valid instrument.