'Trial Sequential Analysis' for Error Control and Inference in Sequential Meta-Analyses R package RTSA version 0.2.2 CRAN Task View: MetaAnalysis (https://CRAN.R-project.org/view=MetaAnalysis) Frequentist sequential meta-analysis based on 'Trial Sequential Analysis' (TSA) in programmed in Java by the Copenhagen Trial Unit (CTU). The primary function is the calculation of group sequential designs for meta-analysis to be used for planning and analysis of both prospective and retrospective sequential meta-analyses to preserve type-I-error control under sequential testing. 'RTSA' includes tools for sample size and trial size calculation for meta-analysis and core meta-analyses methods such as fixed-effect and random-effects models and forest plots. TSA is described in Wetterslev et. al (2008) <doi:10.1016/j.jclinepi.2007.03.013>. The methods for deriving the group sequential designs are based on Jennison and Turnbull (1999, ISBN:9780849303166). Software Depends: R (>= 3.5.0) Imports: stats, metafor, ggplot2, scales, Rcpp (>= 0.11.0) LinkingTo: Rcpp Suggests: gsDesign, CompQuadForm, dplyr, kableExtra, rmarkdown, knitr, bookdown, gridExtra, testthat (>= 3.0.0) Anne Lyngholm Soerensen <lynganne@gmail.com> Comprehensive R Archive Network (CRAN) Anne Lyngholm Soerensen [aut, cre, trl], Markus Harboe Olsen [aut, ctr], Theis Lange [ctr], Christian Gluud [ctr] GPL (>= 2) 2023-11-23 application/tgz https://CRAN.R-project.org/package=RTSA doi:10.32614/CRAN.package.RTSA