Background: There is a small body of research on improving the clarity of abstracts in general that is relevant to improving the clarity of abstracts of systematic reviews.
Objectives: To summarize this earlier research and indicate its implications for writing the abstracts of systematic reviews.
Method: Literature review with commentary on three main features affecting the clarity of abstracts: their language, structure, and typographical presentation.
Conclusions: The abstracts of systematic reviews should be easier to read than the abstracts of medical research articles, as they are targeted at a wider audience. The aims, methods, results, and conclusions of systematic reviews need to be presented in a consistent way to help search and retrieval. The typographic detailing of the abstracts (type-sizes, spacing, and weights) should be planned to help, rather than confuse, the reader.