WREstimates: An R Package for Win-Ratio Sample Size and Power Calculations.

INTRODUCTION: The win-ratio has great potential for determining the overall efficacy of treatments and therapies in clinical trials, as its ability to hierarchically account for multiple endpoints provides a holistic metric of the treatment effect. For the win-ratio to become a prominent and reliable statistical method outside of cardiovascular disease, a straightforward approach to study design, particularly in terms of power and sample size determination, is needed. METHODS: Using an appropriate method for determining these metrics is vital to ensure the validity of the results obtained in a study. RESULTS: The WRestimates package provides easy-to-use functions that can be used for determining the required sample size and power of studies implementing the win-ratio. CONCLUSION: These methods enable the calculation of sample size and power based on estimands or pilot data, thereby eliminating the need for complex simulation-based methods that require numerous assumptions about the data.