A further use for the Harvest plot: a novel method for the presentation of data synthesis.

When performing a systematic review, whether or not a meta-analysis is performed, graphical displays can be useful. Data do still need to be described, ideally in graphical form. The Harvest plot has been developed to display combined data from several studies that allows demonstration of not only effect but also study quality. We describe a modification to the Harvest plot that allows the presentation of data that normally could not be included in a forest plot meta-analysis and allows extra information to be displayed. Using specific examples, we describe how the arrangement of studies, height of the bars and additional information can be used to enhance the plot. This is an important development, which by fulfilling Tufte's nine requirements for graphical presentation, allows researchers to display evidence in a flexible way. This means readers can follow an argument in a clear and efficient manner without the need for large volumes of descriptive text.