Validation Study of Maternal Recall on Breastfeeding Duration 6 Years After Childbirth

Background: Breastfeeding duration is an important indicator commonly measured in maternal and child health and nutrition research. Maternal short-term recall for both initiation and duration of breastfeeding has been shown to be valid; however, validity of long-term recall is not well understood. Research aim: This study aims to assess the validity of maternal recall of breastfeeding duration 6 years after childbirth and its association with sociodemographic factors. Methods: Among 635 mother-child pairs, breastfeeding duration data collected monthly throughout the 1st year after childbirth in the Infant Feeding Practices Study II (IFPS II) were compared to recall data obtained 6 years later during the Year 6 Follow-Up. The intraclass correlation coefficient (ICC) and Bland-Altman plots were examined to study the agreement between the two data sets. Sociodemographic factors associated with accurate recall to within 1 month of the IFPS II breastfeeding duration were assessed using multivariable logistic regression modeling. Results: Maternal recall of breastfeeding duration was found to be valid 6 years after childbirth with a small median overall bias (1 week) toward overestimation. The overall concordance was high (ICC = 0.84), except for high school graduates (ICC = 0.63) and smokers (ICC = 0.61). Smokers (adjusted odds ratio = 0.52; 95% confidence interval [0.4, 0.8]) and multiparous women (adjusted odds ratio = 0.57; 95% confidence interval [0.4, 0.9]) were also less likely to give an accurate recall of their breastfeeding duration to within 1 month. Conclusion: Our study found that maternal recall of breastfeeding duration varies by sociodemographic factors but is accurate 6 years after childbirth.