There are significant flaws in the design and reporting in peer-reviewed journals of many biomedical research studies using laboratory animals, according to a survey led by the UK-based National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3RS).

For example, the researchers found that only 59% of the studies they looked at stated the hypothesis or objective of the study and the number and characteristics of the animals used.

Most of the papers surveyed did not use randomisation (88%) or blinding (86%) to reduce bias in animal selection and outcome assessment. And only 70% of the published studies that employed statistical methods described these methods and presented the results “with a measure of error or variability”, the NC3RS and its colleagues reported.

The survey, which was published online in the open-access journal PLoS ONE, was co-funded by the NC3RS and the US National Institutes of Health/Office of Laboratory Animal Welfare. The team led by Carol Kilkenny of the NC3RS analysed 271 published studies involving research on live rats, mice and non-human primates, carried out in publicly funded research establishments in the UK and the US.

This is “the statistical population that dominates the biomedical research literature, so our results are important and, indeed, indicate cause for concern”, Kilkenny et al commented. The authors of scientific publications have a responsibility to describe their experimental and statistical methods and results comprehensively, accurately and transparently, while journal editors share the responsibility of ensuring that published studies meet these criteria, they argued.

This is “particularly pertinent for research involving animals, as poorly designed and reported experiments raise ethical as well as scientific concerns”, the authors added. While recognising that in some studies not all of the criteria assessed for the survey (e.g., the sex of the animas) would necessarily have a marked impact on overall findings, they insisted there were “principles at stake – namely the transparency, reproducibility and reliability of scientific publications”.

The NC3RS called for “serious efforts” to improve the experimental design and reporting quality of biomedical research involving animals. Raising awareness that these problems exist will be the first step, it said.

The NC3RS is also working with researchers, journal editors and funding bodies to build on the results of the survey by developing a set of reporting guidelines that will help these stakeholders “take appropriate steps to improve the quality and transparency of reporting in the scientific publications with which they are associated”.