Practical guide to sample size calculations: non-inferiority and equivalence trials

Area of Science:

• Clinical Trials
• Biostatistics
• Statistical Methods

Background:

• Sample size justification is essential for robust clinical trial design.
• Accurate sample size estimation ensures meaningful and reliable trial outcomes.
• Determining the required number of participants can be complex.

Purpose of the Study:

• To summarize the steps for conducting sample size calculations.
• To provide guidance for non-inferiority and equivalence trials.
• To illustrate calculations with practical examples and the SampSize app.

Main Methods:

• Summarizing established methodologies for sample size calculation.
• Detailing the components necessary for accurate sample size determination.
• Demonstrating manual calculation methods and app-based approaches.

Main Results:

• Clear steps for sample size calculation in non-inferiority and equivalence trials are presented.
• Practical examples facilitate understanding and application of the methods.
• The SampSize app is introduced as a tool for sample size calculations.

Conclusions:

• This paper provides a practical guide to sample size calculations for specific trial types.
• Researchers can use these methods and examples to ensure adequate participant numbers.
• The SampSize app offers a user-friendly approach to sample size determination.