More maths, fewer mice: web tool helps reduce lab animal use

More maths, fewer mice: web tool helps reduce lab animal use

In clinical efficacy trials for medical treatments, mathematical corrections are often used during the course of the study to optimise the number of participating patients. In earlier stages of research, involving laboratory animals, such mathematical corrections are not yet common.However, they could help reduce the number of animal experiments and thus the number of laboratory animals required.Research at the Vrije Universiteit Brussel by PhD student Susanne Blotwijk, attached to Professor Kurt Barbé’s Biostatistics and Medical Informatics research group, is now making this possible.

Intermediate or interim analyses have been used in clinical trials for decades. Additional analyses are often performed to improve the quality of the original experiment design. Investigating whether a treatment works can sometimes take years.

Researcher Susanne Blotwijk puts the problem into focus: “If it is clear before the end of the study that a treatment works, how ethical is it to deny people outside the study access to this treatment? Conversely, if it’s clear that it doesn’t work, how can you justify recruiting even more patients for your research?”

Of course, changing the experiment design should not be done lightly and requires mathematical corrections to ensure the results and conclusions remain reliable. These corrections are being made in clinical trials. However, for earlier stages of research involving laboratory animals, these corrections are not valid because of the large differences in the number of participants.

Adjustments for clinical trials are calculated on samples with hundreds or thousands of participants. To perform interim analyses in animal experiments, the mathematical corrections commonly used in clinical trials need to be redesigned, specifically tailored to much more limited animal experiments.

“That is exactly what our research deals with: how to calculate these corrections,” says Blotwijk. “To make performing the corrections possible for biomedical researchers in their experiments, we have developed an open-source web tool that anyone can use for free. The software helps optimise the experiment and the number of lab animals needed. A correct sample size is thus calculated and maths can contribute to further reducing the use of laboratory animals.”

The web tool will be presented on 21 September during the IC-3Rs symposium at the VUB Health Campus in Jette. The motto is more science, more care, less animals. The Innovation Centre IC3Rs is a VUB initiative started by emeritus professor Vera Rogiers to increase awareness and knowledge around the “3R” principles in animal experimentation: replacement, reduction, refinement. Alongside Sciensano, VUB is also coordinator of the Re-Place platform, where Belgian researchers share their knowledge of new alternatives to animal testing. The online platform, which is supported by the federal and Flemish governments, has already gathered 200 alternative methods.


[email protected]

The symposium takes place on 21 September from 9.00 to 16.30 on the VUB Health Campus in Jette (Building A – Auditorium Vanden Driessche).


About Press - Vrije Universiteit Brussel

Vrije Universiteit Brussel is an internationally oriented university in Brussels, the heart of Europe. By providing excellent research and education on a human scale, VUB wants to make an active and committed contribution to a better society.

The World Needs You

The Vrije Universiteit Brussel assumes its scientific and social responsibility with love and decisiveness. That’s why VUB launched the platform De Wereld Heeft Je Nodig – The World Needs You, which brings together ideas, actions and projects based on six Ps. The first P stands for People, because that’s what it’s all about: giving people equal opportunities, prosperity, welfare, respect. Peace is about fighting injustice, big and small, in the world. Prosperity combats poverty and inequality. Planet stands for actions on biodiversity, climate, air quality, animal rights... With Partnership, VUB is looking for joint actions to make the world a better place. The sixth and last P is for Poincaré, the French philosopher Henri Poincaré, from whom VUB derives its motto that thinking should submit to nothing except the facts themselves. VUB is an ‘urban engaged university’, strongly anchored in Brussels and Europe and working according to the principles of free research.


Press - Vrije Universiteit Brussel
Pleinlaan 2
1050 Brussel