Sample size determination for alternate periods of use study designs with binary responses

Area of Science:

• Biostatistics
• Clinical Trial Design
• Pharmaceutical Research

Background:

• Standard crossover designs are often modified in practice due to logistical constraints.
• Variations arise from external product use with minimal carryover effects and event-driven or subject-dictated study periods.

Purpose of the Study:

• To offer guidance on sample size determination for nonstandard crossover study designs.
• To address practical modifications of crossover designs in real-world research settings.
• To aid researchers in calculating sample sizes for estimating treatment efficacy differences.

Main Methods:

• The article examines several variations of standard crossover designs.
• It details the data structure and computational methods for variance estimation.
• Sample size formulas are provided for unbiased estimators of efficacy differences.

Main Results:

• The study covers popular crossover designs adapted for specific practical scenarios.
• It presents methodologies for calculating sample sizes in nonstandard situations.
• Guidance is offered for researchers to determine appropriate sample sizes.

Conclusions:

• The findings aim to assist a broad audience in addressing sample size questions for unique study designs.
• A simulation study highlights the importance of verifying sample size adequacy for achieving desired statistical power.
• Promoting best practices in sample size determination ensures the reliability of efficacy estimates.