Which statement best defines Reduction in the 3Rs?

• A. Replacing animals with computer models.
• B. Increasing the number of animals to enhance statistical power.
• C. Minimizing the number of animals used through efficient study design and statistics.
• D. Eliminating all control groups.

Answer: (C)

Reduction means using the smallest number of animals needed to obtain reliable scientific results by planning efficient study designs and applying appropriate statistics. The idea is to maximize the information gained from each animal and to determine the minimum sample size that still provides valid conclusions, often through power analyses, robust experimental designs (such as within-subject or factorial designs when appropriate), and careful planning of endpoints. This helps prevent waste and aligns with ethical obligations to minimize animal use while preserving study quality.

Why this fits best: it directly targets the number of animals used, unlike Replacement (which seeks non-animal methods) or approaches that would increase or waste animal use. It’s also not about removing essential controls or compromising scientific integrity, which would be unethical and invalid.