You and your research report: implementing the ARRIVE reporting guideline

Publishing a research report is fundamental for disseminating new scientific knowledge; and complete, accurate, and transparent reporting is an integral part of responsible research conduct. In order to fulfill their function as reliable and responsible disseminators of new scientific knowledge, journals must ensure that authors include a complete, accurate and balanced account of what was done and what was found during a research investigation in their reports. One of the additional responsibilities of a scientific journal which publishes the results of animal-based investigations is to ensure that no scientific article reports transgressions against experimental animals. ¹ These transgressions may take various forms, such as the misuse of anesthetics and/or analgesics and inappropriate methods of care, housing, and husbandry.

Manuscripts submitted to biomedical journals have uniform requirements, and journals recommend that authors describe their selection of observational or experimental animals with a description of the source population in their report. ² Compliance with these recommendations enables objective assessment of the biological significance of the investigation’s results.^3,4

In 2012, the International Association of Veterinary Editors revised their author guidelines. ⁵ In these revised guidelines, a compulsory animal welfare element was added because many articles in veterinary journals lacked crucial information on animal welfare and ethical issues. Specifically, these revised guidelines state:

All journals publishing studies in which experimental or client-owned animals are used should have a clear editorial policy on animal welfare ethics.

The policy should appear prominently in the instructions for authors and referees.

Guidelines should indicate that recommendations apply to all vertebrate (and specified invertebrate) animals and not just those reared for and used in the laboratory.

Policies should indicate any journal-specific requirements for animal welfare and demand adherence to relevant institutional, national, and international guidelines.

Policies should make clear that failure to meet ethical concerns regarding animal welfare will result in manuscript rejection.

Journals should require author declaration of compliance with animal welfare and ethical guidelines.

The revised guidelines also state that any article that describes animal abuse should not be published.

Compliance with these recommendations and guidelines by authors is not evident in reports of animal-based investigations. Kilkenny and her colleagues ⁶ surveyed 271 publications for detailed information on the objective or hypothesis of the investigations, and the number, sex, age and/or weight of animals that were used in the study, and the experimental and statistical methods employed. They found that only 59% of the reports stated the hypothesis or objective of the investigations, and gave information on the number and characteristics of the animals that were used in the investigation.

Reporting guidelines have become practical tools for achieving high reporting standards of health research.^7,8 Their use by authors improves the reliability and value of research reports and decreases the number of excusable reporting errors. Their use in the publishing and peer-review processes prevents omission of key information, complements other safeguards, such as the public availability of research protocols, and helps to uncover bad research practice(s).

In 2010, two reporting guidelines for animal-based investigations were published. The first guideline, ‘a gold standard publication checklist’, was published by Hooijmans et al. ⁹ in May. In this guideline, the items on the checklist were selected after a literature search for those factors which were decisive in determining the outcome of an animal-based investigation. Its authors claim that their checklist would make future systematic reviews and meta-analyses of animal-based investigations possible, would allow others to replicate and build on previously published work, reduce the number of animals that are needed in animal experimentation (reduction), improve animal welfare (refinement) and, above all, improve the quality of reports of an animal-based investigation. The second guideline, the ARRIVE (Animals in Research: Reporting In Vivo Experiments) reporting guideline, was published by Kilkenny and her colleagues ¹⁰ in June, and comprises a checklist of recommended items for inclusion in reports of an animal-based investigation. All items in the ARRIVE checklist were selected in order to promote high-quality, comprehensive reporting and enable an accurate and critical review of what was done and what was found in the investigation. Since the publication of the ARRIVE reporting guideline, 600 journals have endorsed its use, have incorporated the guideline into their ‘Instructions for Authors’, and have encouraged authors, reviewers, and journal editors to use the guideline when preparing their reports and reviewing the papers. Nevertheless, editorial implementation of this guideline has not been carried out effectively because authors, reviewers, and journal editors have ignored the guideline.^11,12

Laboratory Animals is a journal which operates internationally and publishes peer-reviewed original papers and reviews on all aspects of the use of animals in biomedical research. Accordingly, the journal will only publish reports that conform with the accepted principles of animal use in biomedical science, namely those that are specified in the European Convention for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes and its appendices, and/or the National Research Council Guide for the Care and Use of Laboratory Animals. Laboratory Animals is also one of the 600 journals which has endorsed the ARRIVE reporting guideline. The goal of the ARRIVE reporting guideline is not to be prescriptive or proscriptive, but rather to delineate a minimum set of standards that should be routinely considered when preparing a report and/or evaluating the results of an animal-based investigation. ¹³ However, allowing authors to selectively choose or cherry-pick the recommendations of the ARRIVE reporting guideline devalues a journal’s endorsement of the guideline and makes its implementation aimless, haphazard, and inconsistent. Hence, implementation of the ARRIVE reporting guideline by Laboratory Animals will be authoritarian: authors must provide details on (a) the health and characteristics [species, strain, sex, developmental stage, source, microbiological status, immune status, and genetic background] of their experimental animals, (b) the care, housing, and husbandry of their experimental animals before, during, and after each procedure or intervention and/or after completion of the investigation, and (c) the fate of their experimental animals. The reporting of such details will supplement the required information on each experimental procedure, the pharmacological and non-pharmacological interventions, the humane endpoints, the study design, the ethical review permissions, and relevant licenses.

Why should an author include these details in a report? The answer to this and other questions of this nature depends on the specific purpose or objective of or hypothesis that is to be tested in an animal-based investigation. For example, reporting the sex of experimental animals is meaningful because every experimental animal has a gender, ¹⁴ and this influences many molecular and cellular processes, the animal’s physiology and behavior, and its impacts on a wide range of diseases. Failure to report the sex of experimental animals will not inform readers of sexual dimorphisms in a molecular process or the sex-dependency of a particular behavior, and potentially results in inadequate health care for both sexes. Reporting on the health, characteristics, housing, and husbandry of the animals before, during, and after experiments is also meaningful, especially in animal-based investigations of inflammatory diseases.^15,16 The gastrointestinal microbiota has diverse biological functions in the host, and its composition is influenced by host genetic factors as well as the laboratory environment, such as the exposure to microorganisms and diet, amongst others. Since the gastrointestinal microbiota is a significant source of variation between individual animals, researchers need to take all potential levels of influence and variance on the microbiota into account when designing animal-based investigations of inflammatory diseases and interpreting the results of such studies.

Endorsement of a reporting guideline is worthless without a change in the publication process,^11,13 and implementing a reporting guideline will require a concerted effort by and teamwork between authors, reviewers, and journal editors in order to render research reports complete, accurate, valuable, and useful. ¹⁷ The journal’s editorial team believes that the ARRIVE reporting guideline will undergo continuous evaluation and refinement by all stakeholders in order to achieve consensual consolidation, as evidenced by the recent publication of the National Institutes of Health’s Principles and Guidelines for Reporting Preclinical Research, ¹⁷ and the introduction of the STAR Methods in Cell Press journals. ¹⁸ Accordingly, implementation of the ARRIVE reporting guideline by Laboratory Animals should be viewed as a multi-targeted strategy whose aims are to (a) increase the transparency and clarity of reports, the reproducibility of experimental results, and the robustness of assessment in laboratory animal sciences, (b) maximize the utility of the information that is gained from every experimental animal and every animal-based investigation, (c) safeguard the welfare of experimental animals, (d) ensure application of the 3Rs (replacement, reduction and refinement) in the conduct of animal-based research, (e) prevent unnecessary animal use, and (f) satisfy the demands of society and regulators for good quality science and high levels of regulatory compliance.