Although RevMan can produce forest plots and funnel plots, it may be appropriate to include other types of figures in a review. Examples include:
‘overview’ forest plots, where each line represents a meta-analysis rather than a study (for example, to illustrate multiple subgroup analyses or sensitivity analyses);
plots illustrating meta-regression analyses; and
L’Abbé plots.
Such plots may be produced in software other than RevMan and included as an ‘additional’ figure. Photographs and diagrams may be included in the same way for use in other parts of a Cochrane review.
Additional figures should seldom be required, and should not be used to draw forest plots that could be drawn using RevMan. Where possible, figures should be produced using statistical software packages that produce appropriate publication-quality graphics, such as Stata, SAS, SPSS, S-Plus or specialized meta-analysis software. General-purpose spreadsheet programs may not provide suitable flexibility nor produce output of adequate quality.
A separate document, Considerations and recommendations for figures in Cochrane reviews: Graphs of statistical data, provides extensive guidance on the content of additional figures that illustrate numerical data (available from www.cochrane.org/handbook). The document includes descriptions and recommendations for the plots listed above and several others. Authors should refer to this document before submitting a review containing additional figures. All additional figures should be assessed by a statistical editor or advisor prior to submission of a Cochrane review to the CDSR. Authors should be aware that additional figures can often be large and take up valuable storage space on the Cochrane Library. Guidance on technical aspects of additional figures is available among the RevMan documentation.
The ability to incorporate additional figures in RevMan technically allows authors to attach tables as graphics files. Authors are discouraged from doing this due to the high volume of storage space taken up by graphics files. Authors are instead asked to use the Additional tables function, which is provided for this purpose.