Multi laboratory studies improve reproducibility of animal research

Pre-clinical animal research is typically based on single laboratory studies conducted under highly standardized conditions, a practice that is universally encouraged in animal science courses and textbooks. In a new study in PLOS Biology, researchers from the Universities of Bern and Edinburgh demonstrate that such insistence on uniformity risks producing results that are only valid under very specific conditions. In contrast, multi-laboratory studies that are based on diversity, substantially increased the reproducibility of animal experiments, which could help to further reduce the number of animals used for research. The researchers used simulations based on 440 pre-clinical studies on 13 different experimental treatments in animal models of stroke, heart attack, and breast cancer, and could show that multi-laboratory studies can significantly improve the reproducibility of results. To simulate multi-laboratory studies, the researchers combined data from several individual studies, as if several laboratories had carried them out together. They found that the results of single-laboratory studies were very different, while multi-laboratory studies with two, three or four test laboratories, produced much more similar results, thereby increasing reproducibility without a need for larger sample sizes. "Our findings demonstrate, that standardisation in animal testing is an important cause of poor reproducibility, as it ignores biologically relevant variation," says lead author Prof. Hanno Würbel from the Animal Welfare Division at the University of Bern. Single-laboratory studies produced no accurate estimate