Turner et al. BMC Public Health 2010, 10:170 http://www.biomedcentral.com/1471-2458/10/170 establishing processes to prioritise reviews in these areas of identified need and substantial morbidity and mortality. Also, while The Cochrane Collaboration is developing methods for reviews of diagnostic studies, the Cochrane Database of Systematic Reviews does not currently include reviews of diagnosis, but only therapy. As a result, Cochrane reviews cannot inform decisions about diagnostic approaches, limiting their potential contribu- tion to clinical practice guidelines. Several issues impact on the potential relevance of the Cochrane reviews identified. One is the context in which most of the primary studies included in systema- tic reviews are conducted. The majority of these primary studies are undertaken in stable, developed countries, rather than unstable, resource-poor settings, where large scale emergencies are most common, and have the lar- gest impact on increasing morbidity and mortality. This was particularly clear in the Cochrane reviews evaluating the impact of various forms of dietary supplementation. In many of these reviews the primary studies were not carried out in populations, like those seen in crisis situa- tions, where dietary deficiencies are common. The effects of the supplements evaluated are likely to be very different in these settings, compared to those in which the studies were largely carried out. This highlights the importance of documenting the context of primary research studies included in systematic reviews. When evidence-based guidelines make recommenda- tions for practice, they often use evidence which was generated in contexts that are different from the one in which the guideline will be applied. In some situations evidence is available that was generated in a very similar context. However where this type of immediately rele- vant evidence is not available, guideline developers rely on other evidence, and draw conclusions about whether and/or how it is likely to apply in their context. The degree to which the context impacts on the applicability of the research varies with the nature of the clinical practice. It is difficult to tightly define terms like ‘crisis’, ‘disas- ter’ and ‘emergency’. We chose a very broad definition “crisis settings such as those resulting from natural dis- asters like earthquake, famine and flood, as well as man- made disasters like civil war”, designed to be inclusive, but to differentiate from what might be considered ‘stable’ situations in resource-poor settings. However the threshold between crisis and non-crisis is essentially arbitrary and there will always be grey areas. There are many examples where ‘normal’ conditions in resource- poor settings have deteriorated so that they could rea- sonably be described as crisis situations and also where crisis situations have become so chronic and entrenched that they are essentially ‘stable’. Page 6 of 12 In developing guidelines for crisis situations, there will be times when it is appropriate to base recommendations on evidence established in stable situations and other times when the evidence must be generated in crisis set- tings to be relevant to the practice in question. Similarly some guidelines developed for use in stable situations may be relevant and appropriate for use in crisis situations. The nature of crisis situations varies widely. Crises arise from many different causes, and take place in contexts with widely varying health infrastructure, staff availability, geography and underlying health problems, etc. All of these factors will affect the relevance of research and guidelines generated in other settings. A second factor impacting on the potential relevance is the availability of the interventions evaluated in the Cochrane reviews. While we attempted to include only those reviews addressing interventions which were potentially feasible in crisis settings (guided by the inter- ventions recommended by the guidelines themselves); in the aftermath of emergencies, clinicians are often work- ing with a very limited toolkit of equipment and drugs, and these may vary from one situation to another. As a result, some of the reviews which we believe might be potentially relevant may recommend interventions which are not affordable or practical in some crisis set- tings. However, the large number of potentially relevant Cochrane reviews identified suggests that, even taking these factors into account, Cochrane reviews can still make a substantial contribution to supporting health care decision-making in these contexts. A relatively small percentage of the Cochrane reviews identified as being potentially relevant to informing guide- lines for perinatal and child health in crisis settings currently have summaries in Evidence Aid. So the results of these reviews are only available to those who have access to the full text of The Cochrane Library. As a result The Cochrane Collaboration is missing an opportunity to provide evidence to support humanitarian organisations developing guidelines in these areas. This gap may result from a lack of awareness that the results of these reviews would potentially be valuable in these settings, or, perhaps more likely, from time and resource limitations on the production of the Evidence Aid summaries, a process that requires a substantial investment of time and intellect. This review is limited by our focus on guidelines in the field of perinatal and child health, which may not be representative of the state of guidelines in other areas of emergency health care. However infants, children and pregnant women are particularly at risk in the aftermath of emergencies, and so we feel this focus is reasonable, if largely pragmatic. The review was also limited to those guidelines that were available in English on the internet. High quality evidence-based guidelines relevant to this area may have been developed but not made