TY - JOUR T1 - Need for more and better implementation science in global health JF - BMJ Global Health DO - 10.1136/bmjgh-2016-000115 VL - 1 IS - 2 SP - e000115 AU - Valéry Ridde Y1 - 2016/08/01 UR - http://gh.bmj.com/content/1/2/e000115.abstract N2 - ‘We know what we have to do, but we don't know how to do it’ has been a recurring comment among global health actors for a long time. In 2010, for example, the United Nations affirmed that ‘we know what works’1 in taking care of the health of women and children. The WHO Commission on the Social Determinants of Health (2008) has highlighted effective interventions to improve the health of populations and to establish health equity.2 However, while the content of interventions, which are theoretically effective, are relatively well known, their level of coverage is weak.3 Furthermore, the conditions of their implementation are less understood. An old meta-analysis shows that the potential effectiveness of interventions is reduced by 50% because of multiple contextual factors which act against the implementation.4 Therefore, it is not enough to know if a health intervention is effective; it is also necessary to understand why the intervention works, how, for whom and in which contexts. It is here where implementation science is an undeniable aid.In this editorial, the focus will not be on the controversies concerning the definition of implementation science or the academic arguments made in order to appropriate or better sell the training of implementation science. Essentially, what is of interest is to call on the community of students, researchers, implementers and donors to commit themselves to further and a better quality research in order to have a greater understanding of how to implement health interventions. To quote Joseph Durlak, an important author in this field, ‘studying programme implementation is not easy but it is essential’.5 Implementation is comprised of one or several processes organised in a particular context so as to bring about the desired changes of an intervention (whether policy, programme or project) through the means … ER -