GenTwoArmsTrialSize: An R Statistical Software Package to estimate Generalized Two Arms Randomized Clinical Trial Sample Size

TL;DR

The paper introduces 'GenTwoArmsTrialSize', an R package that enables comprehensive sample size estimation for two-arm clinical trials across multiple scenarios, considering various endpoints, designs, and real-world issues.

Contribution

It provides the first standalone R package for generalized sample size estimation in two-arm trials, covering diverse hypotheses, designs, and practical considerations.

Findings

Supports 24 different trial scenarios

Includes four endpoint types and two treatment designs

Demonstrates impact of noncompliance and follow-up loss

Abstract

The precise calculation of sample sizes is a crucial aspect in the design of clinical trials particularly for pharmaceutical statisticians. While various R statistical software packages have been developed by researchers to estimate required sample sizes under different assumptions, there has been a notable absence of a standalone R statistical software package that allows researchers to comprehensively estimate sample sizes under generalized scenarios. This paper introduces the R statistical software package "GenTwoArmsTrialSize" available on the Comprehensive R Archive Network (CRAN), designed for estimating the required sample size in two-arm clinical trials. The package incorporates four endpoint types, two trial treatment designs, four types of hypothesis tests, as well as considerations for noncompliance and loss of follow-up, providing researchers with the capability to estimate sample sizes across 24 scenarios. To facilitate understanding of the estimation process and illuminate the impact of noncompliance and loss of follow-up on the size and variability of estimations, the paper includes four hypothetical examples and one applied example. The discussion encompasses the package's limitations and outlines directions for future extensions and improvements.