Richter Veronika, Muche Rainer, Mayer Benjamin
a Institute of Epidemiology and Medical Biometry , Ulm University , Ulm , Germany.
J Appl Anim Welf Sci. 2018 Oct-Dec;21(4):325-333. doi: 10.1080/10888705.2018.1423972. Epub 2018 Jan 26.
Statistical sample size calculation is a crucial part of planning nonhuman animal experiments in basic medical research. The 3R principle intends to reduce the number of animals to a sufficient minimum. When planning experiments, one may consider the impact of less rigorous assumptions during sample size determination as it might result in a considerable reduction in the number of required animals. Sample size calculations conducted for 111 biometrical reports were repeated. The original effect size assumptions remained unchanged, but the basic properties (type 1 error 5%, two-sided hypothesis, 80% power) were varied. The analyses showed that a less rigorous assumption on the type 1 error level (one-sided 5% instead of two-sided 5%) was associated with a savings potential of 14% regarding the original number of required animals. Animal experiments are predominantly exploratory studies. In light of the demonstrated potential reduction in the numbers of required animals, researchers should discuss whether less rigorous assumptions during the process of sample size calculation may be reasonable for the purpose of optimizing the number of animals in experiments according to the 3R principle.
统计样本量计算是基础医学研究中非人类动物实验规划的关键部分。3R原则旨在将动物数量减少到足够的最低限度。在规划实验时，人们可能会考虑在样本量确定过程中采用不太严格假设的影响，因为这可能会导致所需动物数量大幅减少。对111份生物统计学报告进行的样本量计算被重复进行。原始效应量假设保持不变，但基本属性（一类错误5%，双侧假设，检验功效80%）有所变化。分析表明，对一类错误水平采用不太严格的假设（单侧5%而非双侧5%），与相对于原始所需动物数量有14%的节省潜力相关。动物实验主要是探索性研究。鉴于已证明的所需动物数量的潜在减少，研究人员应讨论在样本量计算过程中采用不太严格的假设对于根据3R原则优化实验动物数量的目的是否合理。
