Replication is an essential part of the scientific method, yet replication of systematic reviews is too often overlooked, and done unnecessarily or poorly. Excessive replication (doing the same study repeatedly) is unethical and a cause of research wastage. This article provides consensus based guidance on when to replicate and not replicate systematic reviews.

Evidence-based public health decision-making depends on high quality and transparent accounts of what interventions are effective, for whom, how and at what cost. Improving the quality of reporting of randomized and non-randomized study designs through the CONSORT and TREND statements has had a marked impact on the quality of study designs. However, public health users of systematic reviews have been concerned with the paucity of synthesized information on context, development and rationale, implementation processes and sustainability factors. This paper examines the existing reporting frameworks for research against information sought by users of systematic reviews of public health interventions and suggests additional items that should be considered in future recommendations on the reporting of public health interventions. Intervention model, theoretical and ethical considerations, study design choice, integrity of intervention/process evaluation, context, differential effects and inequalities and sustainability are often overlooked in reports of public health interventions. Population health policy makers need synthesized, detailed and high quality a priori accounts of effective interventions in order to make better progress in tackling population morbidities and inequalities. Adding simple criteria to reporting standards will significantly improve the quality and usefulness of published evidence and increase its impact on public health program planning.

Introduction Each year about 20 million infants of low birth weight are born worldwide, which imposes a heavy burden on healthcare and social systems in developing countries.1 w1 Medical care of low birthweight infants is complex, demands an expensive infrastructure and highly skilled staff, and is often a very disruptive experience for families.2 w2 w3 w4 Premature babies in poorly resourced settings often end up in understaffed and ill equipped neonatal care units, that may be turned into potentially deadly traps by a range of factors colluding—for example, malfunctioning incubators, broken monitors, overcrowding, nosocomial infections, etc. In 1978 Edgar Rey, a Colombian paediatrician concerned with the problems arising from a shortage of incubators and the impact of separating women from newborns in neonatal care units, developed Kangaroo Mother Care (KMC),3 a healthcare technique for low birthweight infants that is at least as effective as traditional care in a neonatal care unit.4 5 Footnotes Additional references w1-w20 are on bmj.com Contributors and sources JGRP and NC were responsible for the general idea, reviewed the literature, and synthesised their experience as KMC providers and researchers. LGC devised the general structure of the paper and contributed with the view point of a family practitioner who is familiar with the theoretical and practical aspects of the method. All authors contributed equally to the preparation and revision of the manuscript. NC provided the illustrations for this article. Competing interests None declared.