Example R code to (1) estimate the sample size for cluster randomized trials with a time-to-event outcome based on the additive hazards mixed model (AHMM), (2) to fit the AHMM to clustered survival data, with bias-corrected sandwich variance estimators, (3) to compute p-values based on AHMM-assisted randomization test in cluster randomized trials, and (4) to execute an (example) simulation study to examine the type I error rate and power for the AHMM. This code is provided by the authors to the reviewers, scientific community, and general public at large as a part of their submission of paper titled: "Design and analysis of cluster randomized trials with time-to-event outcomes under the additive hazards mixed model" to Statistics in Medicine.
Our code expands the work of Professors Jianwen Cai and Dongling Zeng (https://doi.org/10.1111/j.1541-0420.2011.01590.x) and is inspired by their MatLab code which was translated into R as the basis of our new development. The authors (Blaha, Esserman and Li) would like to hereby thank Professors Jianwen Cai and Dongling Zeng for kindly sharing with us with their Matlab code to fit the AHMM.