To improve the quality of animal research and prevent unnecessary repetition, it is important that all animal research be registered worldwide. Currently, about forty percent of research results from animal experiments are not published at all. As a result, knowledge is lost. Researchers also run a greater risk of publication bias: positive results are published sooner and more often than neutral or negative results. This makes its interpretation less reliable. This is the conclusion of Residence in cardiology Mira van der Naald. She obtained her doctorate on her research on September 27.

Animal experiments are used to test the efficacy and safety of therapies. In this way, medical breakthroughs can be realized. For example, when it comes to cardiovascular diseases. Residence in cardiology Mira Van der Naald of the UMC Utrecht explains: "Cardiovascular diseases are, together with cancer, the most common cause of death in our country. I began my research, which was co-funded by the Dutch Heart Foundation, with people with damage to their hearts. In some people with a damaged heart, regular treatment methods are insufficient. For them, new therapies are being sought, such as stem cell therapy. In this therapy, stem cells are injected into the heart muscle. Stem cells can grow into several other cell types, including heart muscle cells. Therefore it is believed they can repair the heart muscle. Unfortunately, this therapy has limited effectiveness to date. In this research field animal research is used to discover new strategies."

Less reliable

Bias in animal research is not uncommon. Mira: "There are several forms of bias that can lead to misinterpretation of results. One form of bias is selection bias. This means that the groups in a study are not comparable. For example, consider two groups of mice that are both fed different food. Another form of bias is HARKing. This means adding or adjusting the hypothesis of a study after results are known. In this way, unexpected results can be presented as if they were expected."

Registering animal testing

Bias in animal testing can be countered in several ways. "For example, by registering animal experiments," Mira explains. This is why researchers from the UMC Utrecht developed preclinicaltrials.eu in collaboration with Radboudumc and the Netherlands Heart Institute. Mira is closely involved in the development of the platform. "The global platform exists for four years now. Researchers can sign up and register their research with laboratory animals free of charge. Anyone with an account gains access to the animal research database. In this way, the quality of animal research can be improved and researchers can easily see which animal experiments have already been done and with what results. Even if those results have not been published, for example because the results were not that positive or groundbreaking."

A new standard

Mira hopes that more and more researchers know how to find preclinicaltrials.eu. Just over 120 studies are currently registered through the platform. "In the coming years I would like to see this number increase. Registration of animal research studies may become the norm as far as I am concerned. To achieve this, it is important that scientists not only focus on study results, but also improve the way of conducting research together. There is also a role for various stakeholders, such as funding bodies. One example is ZonMw. This organization is currently running a pilot where in some cases researchers can only receive funding for animal research if their research is registered on preclinicaltrials.eu."