Rethinking research in breast-feeding: a critique of the evidence base identified in a systematic review of interventions to promote and support breast-feeding.

OBJECTIVE: To appraise critically the relevance and value of the evidence base to promote and support the duration of breast-feeding, with a specific focus on disadvantaged groups.
DESIGN: A systematic review was conducted of intervention studies relevant to enhancing the duration of breast-feeding; topics included public health, public policy, clinical issues, and education, training and practice change. A systematic search was conducted. Eighty studies met the inclusion criteria. Data were systematically extracted and analysed. Full results and recommendations are reported elsewhere. Here a critique of the evidence base--topics, quality and gaps--is reported.
RESULTS: Many studies were substantially methodologically flawed, with problems including small sample sizes, inconsistent definitions of breast-feeding and lack of appropriate outcomes. Few were based on relevant theory. Only a small number of included studies (10%) were conducted in the UK. Very few targeted disadvantaged subgroups of women. No studies of policy initiatives or of community interventions were identified. There were virtually no robust studies of interventions to prevent and treat common clinical problems, or of strategies related to women's health issues. Studies of health professional education and practice change were limited. Cost-effectiveness studies were rare.
CONCLUSIONS: Policy goals both in the UK and internationally support exclusive breast-feeding until 6 months of age. The evidence base to enable women to continue to breast-feed needs to be strengthened to include robust evaluations of policies and practices related to breast-feeding; a step change is needed in the quality and quantity of research funded.