revtools: An R package to support article screening for evidence synthesis.

The field of evidence synthesis is growing rapidly, with a corresponding increase in the number of software tools and workflows to support the construction of systematic reviews, systematic maps, and meta-analyses. Despite much progress, however, a number of problems remain, including slow integration of new statistical or methodological approaches into user-friendly software, low prevalence of open-source software, and poor integration among distinct software tools. These issues hinder the utility and transparency of new methods to the research community. Here, I present revtools, an R package to support article screening during evidence synthesis projects. It provides tools for the import and deduplication of bibliographic data, screening of articles by title or abstract, and visualization of article content using topic models. The software is entirely open-source and combines command-line scripting for experienced programmers with custom-built user interfaces for casual users, with further methods to support article screening to be added over time. revtools provides free access to novel methods in an open-source environment and represents a valuable step in expanding the capacity of R to support evidence synthesis projects.