Promotion of Breastfeeding Intervention Trial (PROBIT): a randomized trial in the Republic of Belarus.

CONTEXT: Current evidence that breastfeeding is beneficial for infant and child health is based exclusively on observational studies. Potential sources of bias in such studies have led to doubts about the magnitude of these health benefits in industrialized countries. OBJECTIVE: To assess the effects of breastfeeding promotion on breastfeeding duration and exclusivity and gastrointestinal and respiratory infection and atopic eczema among infants. DESIGN: The Promotion of Breastfeeding Intervention Trial (PROBIT), a cluster-randomized trial conducted June 1996-December 1997 with a 1-year follow-up. SETTING: Thirty-one maternity hospitals and polyclinics in the Republic of Belarus. PARTICIPANTS: A total of 17 046 mother-infant pairs consisting of full-term singleton infants weighing at least 2500 g and their healthy mothers who intended to breastfeed, 16491 (96.7%) of which completed the entire 12 months of follow-up. INTERVENTIONS: Sites were randomly assigned to receive an experimental intervention (n = 16) modeled on the Baby-Friendly Hospital Initiative of the World Health Organization and United Nations Children's Fund, which emphasizes health care worker assistance with initiating and maintaining breastfeeding and lactation and postnatal breastfeeding support, or a control intervention (n = 15) of continuing usual infant feeding practices and policies. MAIN OUTCOME MEASURES: Duration of any breastfeeding, prevalence of predominant and exclusive breastfeeding at 3 and 6 months of life and occurrence of 1 or more episodes of gastrointestinal tract infection, 2 or more episodes of respiratory tract infection, and atopic eczema during the first 12 months of life, compared between the intervention and control groups. RESULTS: Infants from the intervention sites were significantly more likely than control infants to be breastfed to any degree at 12 months (19.7% vs 11.4%; adjusted odds ratio [OR], 0.47; 95% confidence interval [CI], 0.32-0.69), were more likely to be exclusively breastfed at 3 months (43.3% vs 6.4%; P<.001) and at 6 months (7.9% vs 0.6%; P =.01), and had a significant reduction in the risk of 1 or more gastrointestinal tract infections (9.1% vs 13.2%; adjusted OR, 0.60; 95% CI, 0.40-0.91) and of atopic eczema (3.3% vs 6.3%; adjusted OR, 0.54; 95% CI, 0.31-0.95), but no significant reduction in respiratory tract infection (intervention group, 39.2%; control group, 39.4%; adjusted OR, 0.87; 95% CI, 0.59-1.28). CONCLUSIONS: Our experimental intervention increased the duration and degree (exclusivity) of breastfeeding and decreased the risk of gastrointestinal tract infection and atopic eczema in the first year of life. These results provide a solid scientific underpinning for future interventions to promote breastfeeding.

Promotion of breastfeeding intervention trial (PROBIT): a cluster-randomized trial in the Republic of Belarus. Design, follow-up, and data validation.

This paper summarizes the objectives, design, follow-up, and data validation of a cluster-randomized trial of a breastfeeding promotion intervention modeled on the WHO/UNICEF Baby-Friendly Hospital Initiative (BFHI). Thirty-four hospitals and their affiliated polyclinics in the Republic of Belarus were randomized to receive BFHI training of medical, midwifery, and nursing staffs (experimental group) or to continue their routine practices (control group). All breastfeeding mother-infant dyads were considered eligible for inclusion in the study if the infant was singleton, born at > or = 37 weeks gestation, weighed > or = 2500 grams at birth, and had a 5-minute Apgar score > or = 5, and neither mother nor infant had a medical condition for which breastfeeding was contraindicated. One experimental and one control site refused to accept their randomized allocation and dropped out of the trial. A total of 17,795 mothers were recruited at the 32 remaining sites, and their infants were followed up at 1, 2, 3, 6, 9, and 12 months of age. To our knowledge, this is the largest randomized trial ever undertaken in area of human milk and lactation. Monitoring visits of all experimental and control maternity hospitals and polyclinics were undertaken prior to recruitment and twice more during recruitment and follow-up to ensure compliance with the randomized allocation. Major study outcomes include the occurrence of > or = 1 episode of gastrointestinal infection, > or = 2 respiratory infections, and the duration of breastfeeding, and are analyzed according to randomized allocation ("intention to treat"). One of the 32 remaining study sites was dropped from the trial because of apparently falsified follow-up data, as suggested by an unrealistically low incidence of infection and unrealistically long duration of breastfeeding, and as confirmed by subsequent data audit of polyclinic charts and interviews with mothers of 64 randomly-selected study infants at the site. Smaller random audits at each of the remaining sites showed extremely high concordance between the PROBIT data forms and both the polyclinic charts and maternal interviews, with no evident difference in under- or over-reporting in experimental vs control sites. Of the 17,046 infants recruited from the 31 participating study sites, 16,491 (96.7%) completed the study and only 555 (3.3%) were lost to follow-up. PROBIT's results should help inform decision-making for clinicians, hospitals, industry, and governments concerning the support, protection, and promotion of breastfeeding.