Climate change has been described as the greatest global health threat of the 21st century. Direct impacts on human health will include changing concentrations of particulate matter and aeroallergens, or changes in the geographic range or seasonality of infectious diseases. Indirect impacts will include increased stress on existing health system weaknesses and disproportionate impacts on marginalized and vulnerable populations. Due to the complexity of this area, relevant evidence is complex, heterogenous and potentially unbounded.
Scoping reviews of climate-health topics can be used to develop a broad sense of literature relevant to a research question, and determine patterns and trends. In recent years, several scoping reviews have been published on the health impacts of climate change and extreme weather events. However, there are limitations to available methodological guidelines for conducting scoping reviews in climate-health topics; specific recommendations would improve the rigour and utility of reviews. This presentation will consider challenges to conducting scoping reviews of climate-health topics and present recommendations for future methods.
We conducted a scoping review of scoping reviews on climate-health topics. We extracted the research question or objective, the methods guidance the authors cited, and the definition (if any) of climate change that was used. We combined the findings from this review with the experience of authors on this team to make recommendations.
We identified several areas where further guidance would be useful, including:
Establishing definitions of key terms, including climate change and climate change adaptation, that are workable for evidence synthesis purposes. Climate change, and climate change adaptation, are not simple or straightforward topics. Many scoping reviews equate evidence on the health impacts of extreme weather events as being evidence of the health impacts of climate change itself; however, this approach may not adequately respond to the dynamic nature of climate change-related impacts over the coming years and decades.
Sources of evidence. Existing literature may not always be sufficient to answer particular questions, and scoping review teams may therefore need to find alternative sources, such as expert knowledge, input from members of relevant populations and Indigenous knowledge. Appropriate methods for incorporating this additional input into the scoping review are needed.
Balancing breadth and feasibility of what is included in the scoping review. The health impacts of climate change are, in many cases, not new, but rather differences in existing patterns of disease, exacerbations in pressures on health care systems, etc. This can mean that studies that are relevant to the research question of a scoping review may not be framed from a climate change perspective, and the scoping review will have to be designed to encompass literature from a wide range of disciplines. Review teams may have to consider how to deal with large quantities of citations for screening, and data for inclusion.
Modifications to existing methodological guidelines for conducting scoping reviews are needed to improve the rigour and utility of reviews of climate-health topics.