Rex: R-linked EXcel add-in for statistical analysis of medical and bioinformatics data

Background Microsoft Excel has substantial functionalities for data management and analyses, and has been the most popular software in this field. However, in spite of Excel’s user-friendly interface and functionality for data management, it provides very few functions for in-depth statistical analyses, which has limited its wider application for this purpose. Objective Here, we introduce Rex, an Excel add-in software implementing the powerful analytical and graphical functions of R within Excel. Methods Rex was implemented using three types of programming software: R, JavaScript, and Microsoft VB.Net. Results Rex provides a graphical user interface (GUI) through Excel, and statistical analysis can be conducted by pointing and clicking the menu without programming R. Rex covers a wide range of analyses from basic statistics to advanced analysis, including structural equation modeling, complex sampling design, and machine learning models, making it possible for researchers not skilled in using a command-line interface to conduct in-depth statistical analyses. Most Rex modules are available in a free version for non-commercial use, and it can be used for educational and public purposes. Conclusion In this article, we introduce the framework and features of Rex with illustrative examples of its implementation.