Global evidence synthesis and UK idiosyncrasy: why have recent UK trials had no significant effects on breastfeeding rates?

Breastfeeding is a highly complex physiological, emotional, social and cultural behaviour, and so, in many ways, it is not surprising that to design and deliver effective behaviour change interventions to improve breastfeeding rates are challenging.The World Health Organization recommends exclusive breastfeeding for 6 months (World Health Organization 2003), and this presents a public health policy challenge, particularly for countries like Britain where less than 1% of women currently achieve this (Bolling et al. 2007). Given the diversity of cultures and philosophies underpinning health service systems in different countries, it is unlikely that one generalized intervention will provide a magic bullet to increase breastfeeding.This appears to be the case for the UK, where nine randomized controlled trials reported since 2000 have not significantly improved breastfeeding rates (Morrell et al. 2000; Winterburn et al. 2003; Graffy et al. 2004; Carfoot et al. 2005; Lavender et al. 2005; Muirhead et al. 2006; Wallace et al. 2006; Hoddinott et al. 2009; MacArthur et al. 2009). These trial outcomes differ from the findings of a recent evidence synthesis of international studies reported between 2001 and 2008 (Chung et al. 2008) that breastfeeding interventions are more effective than usual care. An earlier synthesis found that additional lay or professional support increases shortand long-term breastfeeding duration and exclusivity (Britton et al. 2007). So what is going on? Is it the trial design or execution that is problematic? Is it a particular attribute of UK childbearing women or researchers? Are there factors in the health system or the wider environment that mitigate attempts to intervene to improve breastfeeding outcomes? Is it valid to conclude that breastfeeding interventions are unlikely to be generalized across countries in the developed world? This editorial does not provide definitive answers to these questions; rather, we wish to highlight some key themes that are worth unpicking to make progress in this important area. This is particularly relevant in the current economic climate as the use of finite health service resources will come under increasing scrutiny, and evidence-based breastfeeding care will need to compete with other health improvement behaviours. The nine UK trials published since 2000 with nonsignificant breastfeeding outcomes were identified from evidence syntheses and searching trial databases. Most report breastfeeding duration as the primary outcome ranging from hospital discharge until 4 months after birth, with one trial reporting breastfeeding initiation only (MacArthur et al. 2009), and in one trial, the primary outcome was general health status, with breastfeeding as a secondary outcome (Morrell et al. 2000). We systematically critiqued and extracted thematic data from the nine trial reports and process evaluations linked to three of the trials (Morrell & Stapleton 2000; Crowther et al. 2001; Graffy & Taylor 2005; Hoddinott et al. 2010a), looking for explanations for the study findings. One of the co-authors (RS) conducted semi-structured telephone interviews with six principal investigators to ask for their perspectives on why their own trial did not improve breastfeeding outcomes (Seyara 2010). Evidence syntheses tend to focus on who delivers the intervention (professional or lay), whether it is before or after birth or both, whether intervention components are single or multifaceted, and whether the content is either education or support (Britton et al. 2007; Gagnon 2007; Chung et al. 2008; Dyson et al. 2008). In the most recent evidence synthesis for the US Preventive Services Task Force of interventions in primary care (defined as any health service care intervention including hospital care), combining preand post-natal components had a larger effect than either alone (Chung et al. 2008). Interventions that include lay support in a multi-component intervention may be more beneficial than singlecomponent interventions (Chung et al. 2008). The careful use of the word may in the conclusion reflects DOI: 10.1111/j.1740-8709.2011. 00336.x