Trial Sequential Analysis for Meta-Analyses of Hazard Ratios R package tsahr version 0.2.8.17 Performs Trial Sequential Analysis (TSA) for meta-analyses of time-to-event outcomes reported as hazard ratios. Implements the Schoenfeld required-events sample-size formula generalised for unequal allocation, the Diversity (D-squared) heterogeneity adjustment of Wetterslev et al. (2009), and O'Brien-Fleming-type alpha- and beta-spending trial sequential monitoring boundaries computed at the inverse-variance information based on observed study-level log-HR standard errors (not merely event counts), via a compiled (C++) recursive numerical integration engine ported from the R package 'RTSA' (Soerensen, Olsen, Lange and Gluud; an R implementation of the Trial Sequential Analysis software of the Copenhagen Trial Unit, <https://ctu.dk/tools>), with no fixed software-imposed limit on the number of looks (subject to available computational resources). Produces a cumulative Z-curve plot with efficacy, futility, and conventional significance boundaries. Methodology follows Miladinovic et al. (2013) <doi:10.1016/j.jclinepi.2012.11.007> and Wetterslev et al. (2009) <doi:10.1186/1471-2288-9-86>. Software Depends: R (>= 4.0.0) Imports: metafor, readxl, ggplot2 (>= 3.4.0), stats, utils, Rcpp (>= 1.0.0) LinkingTo: Rcpp Suggests: testthat (>= 3.0.0), RTSA Tarak Dhaouadi <dhaouaditarak@yahoo.fr> Comprehensive R Archive Network (CRAN) Tarak Dhaouadi [aut, cre], Anne Lyngholm Soerensen [ctb, cph] (author of the RTSA package, from which the boundary engine is ported), Markus Harboe Olsen [ctb, cph] (author of the RTSA package, from which the boundary engine is ported), Theis Lange [ctb, cph] (author of the RTSA package, from which the boundary engine is ported), Christian Gluud [ctb, cph] (author of the RTSA package, from which the boundary engine is ported) GPL (>= 2) 2026-10-08 application/tgz https://CRAN.R-project.org/package=tsahr doi:10.32614/CRAN.package.tsahr