Sample Size Calculations – Practical Guidance Beyond the Formulae

How many patients are enough?

Behind every sample size lies a series of critical assumptions about treatment effects, variability, risk, and feasibility. These decisions are rarely just statistical; they are clinical and strategic.

This white paper goes beyond the formulas to explore the real-world trade-offs that shape sample size determination. Designed for clinicians and non-statistical stakeholders, it highlights the practical questions that can determine whether a trial is feasible, credible, and truly informative.