Methods

The 10 journals publishing the greatest number of veterinary SRs were identified from the VetSRev²¹ citation database (Centre for Evidence-Based Veterinary Medicine) in April 2023. VetSRev²¹ is a citation database of exclusively SRs from the PubMed²² and CAB Abstracts²³ databases. VetSRev²¹ was created to provide a freely available index to SRs related to veterinary medicine because, as an interdisciplinary subject, it lacked a single comprehensive database. At the time of VetSRev's creation, there was a lack of effective search filters for veterinary-relevant publications.

For studies to be included in VetSRev, they have to meet the following minimum criteria: a methods section with a search strategy, reporting of at least 1 citation database that was searched, and veterinary or animal in the scope of the review. The 10 journals that published the largest number of veterinary SRs were identified by frequency in the VetSRev database. Those 10 journals, listed alphabetically, were:

• Animals²⁴

• Frontiers in Veterinary Science²⁵

• Journal of Animal Science²⁶

• Journal of Dairy Science²⁷

• Parasites and Vectors²⁸

• PLoS Neglected Tropical Diseases²⁹

• PLoS One³⁰

• Preventive Veterinary Medicine³¹

• Transboundary and Emerging Diseases³²

• Zoonoses and Public Health³³

A list of the URLs of these journals’ instructions to authors can be found in Supplementary Table S1.

According to the VetSRev database, these 10 journals selected contained the greatest number of SRs out of all journals in this database. The data that this was based on included 3073 articles published in 1000 journals. The ten journals selected represented 18.41 percent of total articles. The publication time frame for articles in VetSRev was 1992-2022 at the time of the study, with 1992 being the first year that a SR relevant to veterinary medicine was published. There has been an increase in the number of veterinary SRs published since 2018; a future study is planned to investigate the features of these reviews in more detail.

The project team created an online survey form (Forms; Google Corp) to collect information in each journal's instructions to authors guidelines related to SR submissions. The fields included:

• Date the site was accessed and the form filled out

• Journal name

• Does the journal have instructions for authors?

• URL to instructions for authors

• Are SRs specifically mentioned in the instructions to authors?

• Do the instructions for authors for SRs mention reporting guidelines?

  • If yes, are the reporting guidelines recommended or required?

  • If required, do the instructions to authors indicate how the author is to comply?

• URL to instructions to authors for review articles or SRs if different than general instructions to authors

  • If yes, do the instructions for authors indicate a specific reporting guideline for SRs or provide additional information?

  • If yes, which reporting guidelines and was a URL provided for any additional information?

• Can one concisely summarize how the author complies with the instructions for reporting SRs?

Project team individuals were randomly assigned to screen 2 to 3 journals using the form, with at least 2 people screening each journal. Author guidelines on the journal website were identified by each team member using the method of their choice, typically using an internet search engine (Search; Google Corp) or navigating from the journal's homepage. The authors completed the forms in October and November 2023. The 2 individuals responsible for each journal discussed and resolved conflicts and either revised the form results or filled the form out a third time. This was completed by December 2023.

Results

Of the 10 listed journals, only 7 had specific, easy-to-find instructions pertaining to SRs. Two had no mention of SRs. Eight of the 10 journals named PRISMA, a specific SR reporting guideline, as a recommended or required entity (Supplementary Table S1).

The reviewed journals provided variable clarity and specificity in their author guidance regarding reporting guidelines. Four of 10 journals stated specific requirements for reporting guidelines for SRs, 3 journals stated that reporting guidelines should be used, and 1 journal stated that these guidelines were strongly encouraged. In 2 journals, no mention of reporting guidelines was provided.

Each journal was assessed for how easy it was to find information about SRs.

For Animals,³⁴ finding information on SRs required numerous clicks/tabs. After 4 clicks, the information provided indicated that PRISMA¹ guidelines should be used for SRs. Throughout additional directions for SRs, the word “should” was used. However, the word's meaning was never made clear; thus, whether PRISMA¹ or other guidelines were required or recommended was unclear despite stating one should include details about search parameters, methods, a checklist, and a flow chart. They were the only journal to stipulate the registration of protocols with PROSPERO,³⁵ an international database of human registered prospective SRs.

In Frontiers in Veterinary Science,³⁶ depending on how the search for author guidelines was conducted, information about SRs varied. Two to 4 clicks were needed depending on the search style. Information ultimately was evident in the “article types” subsection of the instructions for authors page. Using reporting guidelines with a PRISMA flow diagram was mentioned, with a recommendation for a checklist to be included with the manuscript. This journal discussed the use of reporting guidelines, only requiring the PRISMA flow diagram, not full use of the guidelines. The Journal of Animal Science³⁷ had a general instruction page for all article options, including an author instructions section. Research and reviews were discussed, though SRs specifically were not mentioned, and reviews in general (without clarification) were only by invitation. Going to the journal's homepage or the author submissions page provided clear insight into the journal's requirements and recommendations, but it did not clarify whether SRs are invite only or considered original research. Further, the journal provided no mention of the use of reporting guidelines.

The Journal of Dairy Science³⁸ had a policies document and a style and form document, which provided author information. Reviews, though not specifically SRs, were by invitation only. Potential authors were directed to the American Dairy Science Association for reporting guidelines, where PRISMA is specified for SRs. The policies document said invitations are needed, whereas the style and form document stipulated that SRs were not via invitation. Thus, the ability for an author to find information required 3 or more clicks to get the information needed, and the information provided was contradictory and unclear. However, the journal did state that for SRs and meta-analyses they do prefer the use of reporting items, implying a checklist, and did provide a direct link to the PRISMA site.

For Parasites and Vectors,³⁹ it was challenging to identify specific information for SRs. The information found differed if one came to the journal in different ways (via different internet search parameters). Further, numerous clicks and hyperlinks were needed to obtain information. The “preparing your manuscript” page was the most relevant. However, neither SRs nor the use of reporting guidelines were mentioned at all, preventing determination of requirements, recommendations, and related information.

PLoS Neglected Tropical Diseases⁴⁰ had an author page where SRs were mentioned embedded deep within the information. Reporting guidelines based on PRISMA were required. Authors were directed to the PRISMA website for details. Requirements included submitting the PRISMA guideline, checklist, and flow diagrams with the article. This journal had relatively straightforward information, but it still required multiple clicks before directing authors to another website for information, namely PRISMA, for which a direct URL link was provided.

PLoS One⁴¹ provided clear, consistent, and easily accessible instructions for authors to complete and submit SRs. The journal required PRISMA guidelines, providing a link to the PRISMA site. On our initial review of the journal's instructions to authors, the word “should” was used when stating that submissions “should include a completed PRISMA checklist and flow diagram to accompany the main text.” However, on reviewing the website prior to publication, it was clear that the use of PRISMA reporting guidelines is required, and a link to the site is included. Overall, the instructions were easy to find, required minimal searching, and were specific to SRs.

Preventative Veterinary Medicine's “guide for authors”⁴² was easily located. Guidelines were discussed and recommended (“should be used”), but the methods were not stipulated on our original perusal of the website. However, upon review prior to publication, links to the AVMA http://jama.ama-assn.org/cgi/reprint/283/15/2008 and PRISMA websites were provided, suggesting their use. Only 1 or 2 clicks were needed to obtain the necessary information.

Transboundary and Emerging Diseases⁴³ required 2 clicks to get to the author's page, where one could find author guidelines. The information pertaining to SRs was vague. It mentioned SRs could be submitted under reviews of no specific distinction; however, further down, a statement suggested reporting was strongly encouraged, mentioning a PRISMA statement specifically for SRs. While providing PRISMA as a suggested reporting guideline, they did not provide a link to the website nor state that it was specifically required for submission.

For Zoonoses and Public Health,⁴⁴ one needed to go to the journal's homepage to the “contribute” drop-down, select “author guidelines,” and then find “manuscript categories and requirements.” The initial location where one sees mention of SRs provided no requirements/recommendations. One needed to scroll far down, which could easily be missed and was missed on the first pass by 1 of our reviewers. A statement of encouragement to follow guidelines was noted. Finally, PRISMA and 15 other potential reporting guidelines were mentioned, with links to the appropriate sites.

For those journals where information was included in the general information for authors, using CTRL F (Windows) or Command F (Mac) to find SR information was the most economical way to identify relevant information as it was not always obvious or distinct from the text on other topics.

In summary, 8 of 10 articles mentioned SRs as a specific article type. Eight of 10 journals required, recommended, or mentioned (“should use” or strongly encouraged) the use of reporting guidelines. For all publications that mandated, recommended, or referenced reporting guidelines, 7 of them provided the URL link to PRISMA guidelines.¹

Discussion

This study demonstrated that instructions for authors of SRs varied among journals publishing veterinary SRs. Some instructions were in both locations or were found on the publisher's website and not on the individual journals’ websites, or it was unclear as to what was recommended regardless of whether one navigated to the journal or the publisher site. Further, instructions for SRs were not found in 2 of 10 journals (Journal of Animal Science and Parasites and Vectors), and in 4 journals (Animals, Preventative Veterinary Medicine, Transboundary and Emerging Diseases, and Zoonoses and Public Health) recommendations were made but were potentially confusing in their requirement for reporting guidelines. This supports our hypothesis that instructions for authors pertaining to the writing and reporting of SRs lack consistency and clarity across all platforms.

Given the importance of robustly conducted SRs for guiding clinical practice and future research, the publication of poorly reported SRs is a concern. In addition to the poor overall quality of many veterinary SRs, previous studies^15,45–47 have highlighted issues with reporting compliance in the veterinary literature.

Journals are positioned as a quality-control step with the ability to reject submissions, including SRs that fail to meet methodological and reporting standards.⁴⁸ However, journals often fail to do so despite the availability of guidelines for assessing the quality of submitted SRs and their reporting. Multiple reasons for this failure include potential journal editorial teams’ and peer reviewers’ lack of knowledge about the SR methods and reporting guidelines and potential conflicts of interest. A journal's instructions for authors, if of poor quality or unclear, may be an additional cause contributing to poorly reported SRs. Pauwels et al¹⁹ recently reviewed the instructions for authors submitting SRs to journals in the human medical field and identified numerous deficiencies.

Journal editorial teams and the instructions they provide to authors, including which reporting guidelines to follow, are a vital part of ensuring quality. Despite efforts during the last several decades to standardize medical SRs^49,50 the need for more clarity and standardization of author instructions in veterinary journals persists.

We identify deficiencies in these journals’ instructions to authors, similar to those Pauwels et al¹⁹ identified, and suggest improvements. We hope editorial teams of journals in the veterinary field will use this information to improve their instructions for authors submitting SRs and to address deficiencies in their journals’ review process for these manuscripts.

Inconsistencies and lack of clarity extend to human medical journals as well. However, an article describing best tools and practices for SRs, published in 2023, attempted to highlight inconsistencies in SRs.¹⁸

Efforts to compile reporting guidelines are also ongoing in veterinary medicine. For example, the Equator Network collects reporting guidelines for research involving animals in the Menagerie of Reporting Guidelines Involving Animals.¹² Various commentaries have highlighted the need for standardization.^15,51

This study's findings suggest that corrective actions are warranted from editorial teams and publishers of journals publishing veterinary SRs. The need for clarification and standardization of instructions for authors of SRs in veterinary medicine is like the need recently highlighted for human medical journals.¹⁹ With slightly more than 1,000 active journals in the veterinary medical literature⁵² relative to 100,000 journals in the biomedical literature,⁵³ the relatively compact size of the veterinary medical publishing industry may offer the opportunity to accelerate standardization and increase awareness among authors, reviewers, and readers of veterinary medical articles.

The current study had limitations. The number of journals evaluated was arbitrarily limited to 10. Identifying journals that had published the greatest number of SRs relied on the VetSRev database of the Centre for Evidence-Based Veterinary Medicine at the University of Nottingham. While this database combs CAB Abstracts and PubMed, it is possible the database did not contain all relevant veterinary SRs. The selection of journals for review was intentional and potentially restricted the generalizability of results.

From this study, we found that instructions for authors of SRs in veterinary medical journals were often incomplete, opaque, or poorly explained. We recommend veterinary medical journal editorial teams clarify and coordinate instructions for reporting guidelines and recommend appropriate methodology guidance. Continuing efforts to educate authors, reviewers, and readers about the importance of compliance is paramount. Since SRs represent a “scientifically defensible summary of the current state of knowledge on a topic,”⁴⁶ it is imperative to support required compliance with established reporting standards, like PRISMA,¹ to improve the utilization of well-crafted, well-investigated, well-supported, robust SRs in the field of veterinary medicine.

Supplementary Materials

Supplementary materials are posted online at the journal website: avmajournals.avma.org.

Disclosures

The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.

Funding

The authors have nothing to disclose.

ORCID

E. L. Tramuta-Drobnis https://orcid.org/0000-0001-9157-2052

L. M. Rey https://orcid.org/0000-0002-8283-7693

M. L. Brennan https://orcid.org/0000-0002-4893-6583

M. E. Crews https://orcid.org/0000-0002-4960-5591

E. D. Fausak https://orcid.org/0000-0002-0510-0153

D. J. Marcellin-Little https://orcid.org/0000-0001-6596-5928

H. K. Moberly https://orcid.org/0000-0002-5080-2656

M. L. Whitehead https://orcid.org/0000-0002-9872-8707