Acta Pædiatrica ISSN 0803–5253 REGULAR ARTICLE Promotion of exclusive breastfeeding is not likely to be cost effective in West Africa. A randomized intervention study from Guinea-Bissau Marianne S. Jakobsen (marianne.jakobsen@dadlnet.dk), Morten Sodemann, Sidu Biai, Jens Nielsen, Peter Aaby Bandim Health Project, Indepth Network, Danish Epidemiology Science Centre, Apartado 861, Bissau, Guinea-Bissau; and Statens Serum Institut, 2300 Copenhagen S, Denmark Keywords Anthropometry, Epidemiological study, Exclusive breastfeeding, Guinea-Bissau, Infant mortality and morbidity, Randomized intervention study Correspondence Marianne Skytte Jakobsen, Bandim Health Project, Danish Epidemiology Science Centre, Statens Serum Institut 2300, Copenhagen S, Denmark. Email: marianne.jakobsen@dadlnet.dk Received 2 April 2007; revised 2 June 2007; accepted 23 August 2007 DOI:10.1111/j.1651-2227.2007.00532.x Abstract Aim: To evaluate the impact of promotion of exclusive breastfeeding on infant health in Guinea- Bissau, West Africa, where mortality rates are high, breastfeeding is widely practiced but exclusive breastfeeding is rare. Method: At the Bandim Health Project in Guinea Bissau, West Africa, a birth cohort of 1721 infants were randomized to receive health education: promotion of exclusive breastfeeding for the first 4–6 months of life according to WHO recommendations at the time of the study. All children were followed from birth to 6 months of age. Results: Introduction of both water and weaning food was significantly delayed in the intervention group. However we found no beneficial health effects of the intervention; there was no reduction in mortality in the intervention group compared with the control group (mortality rate ratio: 1.86 (0.79–4.39)), weight at 4–6 months of age was significantly lower in the intervention group (7.10 kg vs. 7.25 kg; Wilcoxon two-sample test: p = 0.03). There was no difference in diarrhoea morbidity and hospitalization rates. Conclusion: Although mothers were sensitive to follow new breastfeeding recommendations, it had no beneficial impact on infant health in this society with traditional, intensive breastfeeding. There seems to be little reason to discourage local practices as long as there are no strong data justifying such a change. INTRODUCTION There is no doubt that breastfeeding is the ideal food for in- fants and it has been documented that an infant needs no supplement and does well easily on breast milk alone up to the age of 6 months (1,2). Therefore exclusive breastfeeding is promoted worldwide by WHO to improve infant and child health (3,4). However, evidence obtained from randomized studies showing that exclusive breastfeeding is beneficial to child health is limited. Only two randomized study, in which mothers were randomized to receive counselling about the benefits of exclusive breastfeeding, have been conducted to evaluate the direct effect of promotion of exclusive breast- feeding on infant morbidity and growth, one from Belarus (5) and one from India (6). A study from Mexico examined, as a secondary outcome, the effect of exclusive breastfeeding promotion on diarrhoea morbidity (7). The ultimate decision of how to feed an infant is taken by its mother or its family and is a product of culture and traditions as well as socioeconomic conditions and well- being of mother and child. It is therefore always a question whether the observed impact of exclusive breastfeeding on child health is due to reverse causality, selection bias, con- founding or a causal effect. Several randomized studies have demonstrated that the proportion of exclusive breastfeed- ing mothers and children can be increased by counselling (7–9). However the knowledge of the impact of exclusive breastfeeding on child health is based mainly on observa- tional studies (10–16). In most low-income countries, health situation of infants is poor and there is a need for effective interventions that are carefully evaluated in order to achieve improvements in in- fant health. Very few settings in low-income countries have the possibility of evaluating the impact of health interven- tions on mortality. However, in Guinea Bissau, West Africa, the Bandim Health Project maintains a demographic health surveillance system making longitudinal follow-up possible. As in most Sub-Saharan countries the population in Guinea Bissau is characterized by high infant mortality and high prevalence of infectious diseases. Almost 100% of the mothers start breastfeeding but only few percent are breast- feeding exclusively. Nonetheless, the tradition is prolonged breastfeeding with a median length of more than 22 months (9). The present randomized study with longitudinal follow- up was designed to examine whether promotion of exclusive breastfeeding is effective in reducing infant morbidity and mortality in Guinea-Bissau. SUBJECTS AND METHOD Study area The Bandim health project The study was conducted at the Bandim Health Project in Guinea-Bissau, West Africa, one of the poorest countries in the world (17). The infant mortality rate is 100/1000 (18) and the case fatality rate among children admitted to the only paediatric ward in the country is almost 15% for children under 5 years of age (19). In the study area, suburban districts 68 C 2007 The Author(s)/Journal Compilation C 2007 Foundation Acta Pædiatrica/Acta Pædiatrica 2008 97, pp. 68–75