Effect of a hospital policy of not accepting free infant formula on in-hospital formula supplementation rates and breast-feeding duration

OBJECTIVE: To investigate the effect of public hospitals in Hong Kong not accepting free infant formula from manufacturers on in-hospital formula supplementation rates and breast-feeding duration. DESIGN: Prospective cohort study. SETTING: In-patient postnatal units of four public hospitals in Hong Kong. SUBJECTS: Two cohorts of breast-feeding mother-infant pairs (n 2560). Cohort 1 (n 1320) was recruited before implementation of the policy to stop accepting free infant formula and cohort 2 (n 1240) was recruited after policy implementation. Participants were followed prospectively for 12 months or until they stopped breast-feeding. RESULTS: The mean number of formula supplements given to infants in the first 24 h was 2·70 (sd 3·11) in cohort 1 and 1·17 (sd 1·94) in cohort 2 (P<0·001). The proportion of infants who were exclusively breast-fed during the hospital stay increased from 17·7 % in cohort 1 to 41·3 % in cohort 2 (P