The reproducibility and validity of preclinical animal experiments has been called into question over the past several years, due, in large part, to the lack of bias-reducing measures reported in scientific literature. Considering that animal experiments are first approved by committees that oversee the use of animals in research, testing and education, a recent study set out to determine whether risk of bias can be detected at earlier stages, before the animal experiments are even conducted.
The study took place in Switzerland, a country which ranks very high in animal protection measures. Here, animal experiments must first be authorized to take place based on a harm-benefit analysis. Protocols are denied authorization if the perceived harm to animals is greater than the anticipated gain in knowledge, and gain of knowledge is based on sound experimental design and conduct.
In this new study, 1,277 applications for animal experiments that had been submitted to the Swiss authorities were examined to determine if they included seven basic bias-reducing measures, including blinding, randomization and sample size calculation. Then, a subset of scientific publications which resulted from these studies were examined to determine how often they included descriptions of these same bias-reducing measures.
Results revealed that bias-reducing measures were rarely described, both in study applications (2%–19%) and in publications (0%–34%). There was a weak correlation which allowed researchers to predict, based on the details provided in the study application, whether a resulting scientific publication would mention bias-reducing measures.
Based on these results, the researchers recognized that authorities who are overseeing animal research (and analyzing the harms and benefits of studies) are doing so without critical information about experimental design. This is problematic, given that any expected benefits from a study are based on that study having scientific validity. It is not enough for authorities to assume that experiments are being conducted with appropriate bias-reducing measures in place; they should be demanding that such measures be present in all applications, and later, in any publications stemming from that research.
Limitations of animal models extend beyond the design, execution and reporting of animal experiments—they center around the core issue of whether the scientific community should be relying on animal models at all. More needs to be done in the scientific community to emphasize the development and utilization of more human-relevant approaches that do not rely on animal models.
Source: Vogt L, Reichlin TS, Nathues C, Wurbel H. (2016) “Authorization of Animal Experiments Is Based on Confidence Rather than Evidence of Scientific Rigor.” PLoS Biol. 14(12).
READ MORE: The lack of bias-reducing measures in reporting is only one of many issues
plaguing animal experimentation. Visit the NAVS website for an examination
of the Failure of the Animal Model.