New guidelines developed by the UK-based National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3RS) to improve standards of reporting for animal experiments have been published online in PLoS Biology and in five other journals.

Formulated in consultation with the scientific community, including researchers, statisticians, journal editors and animal research funders, the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines are aimed at scientists writing up research for publication or involved in peer review.

They consist of a 20-point checklist of essential information that the NC3Rs believes should be included in publications reporting animal research. The aim is to ensure that data from animal experiments can be fully scrutinised and utilised.

An article in PLoS Biology, written by a team of scientists led by Carol Kilkenny of the NC3RS, includes the guidelines in full and can be accessed online at

In an accompanying editorial, Catriona MacCallum, senior editor of PloS Biology, comments: “It is simply unethical to fail to report or to report badly the results of any animal study. We therefore welcome and strongly endorse the initiative of Kilkenny and colleagues”.

The new guidelines also appear, in some cases with accompanying editorials, in the Journal of Gene Medicine; Experimental Physiology; the Journal of Physiology; the British Journal of Pharmacology; and Laboratory Animals. A number of other journals have endorsed the guidelines and incorporated them into their instructions for authors.

Last December, the NC3RS reported the results of a survey, co-funded by the US National Institutes of Health/Office of Laboratory Animal Welfare, that revealed significant flaws in the design and reporting in peer-reviewed journals of many biomedical research studies using laboratory animals.

For example, only 59% of the 271 published studies reviewed stated the hypothesis or objective of the study and the number and characteristics of the animals used, while most of the papers did not use randomisation (88%) or blinding (86%) to reduce bias in animal selection and outcome assessment.

Only 70% of the studies that employed statistical methods described these methods and presented the results with a measure of precision or variability, the survey found.