Plain language summaries: Enabling increased diversity, equity, inclusion and accessibility in scholarly publishing

Plain language summaries (PLS) are accessible, short, peer‐reviewed summaries of scholarly journal articles written in non‐technical language. The aim of PLS is to enable a broader audience of experts and non‐experts to understand the original article. Here, we outline the evidence base for the value and impact of PLS and how they can enable diversity, equity, inclusion and accessibility in scholarly publishing. PLS can diversify readership and authorship, address information inequity, include typically under‐represented stakeholders and provide an accessible route into scholarly literature.

submitting author and for the publisher. This simplicity is particularly beneficial for establishing routine development, for publishers wanting to offer PLS options but have limited infrastructure for hosting multimedia formats, and for authors who are new to the process and may not have access to graphics and digital tools (Young et al., 2014). A further benefit of plain text PLS is discoverability because they can be easily hosted alongside the scientific abstract in front of the paywall in cases of non-open access articles (Khobragade et al., 2022). However, it is also important to note that open access publishing itself is another key driver of discoverability (Schilhan et al., 2021). When tagged correctly by publishers using the XML tag 'plain-languagesummary' in the Other Abstract field, plain text PLS can also be indexed on PubMed-one of the most widely used and accessible biomedical search platforms with over 2.5 million daily users from different stakeholder backgrounds, including patients and support networks (Fiorini et al., 2017;Ossom Williamson & Minter, 2019)-to further improve discoverability and readership (National Information Standards Organization, 2022).
In light of this, there are some journals who require this basic format of PLS for all submissions (e.g., Research Involvement and Engagement, Therapeutic Advances in Drug Safety, and the Journal of Managed Care & Specialty Pharmacy). Also, some research funders, such as the pharmaceutical company Ipsen, have pledged to publish PLS alongside all journal publications of research they support (Ipsen, 2022). We strongly believe that all publishers and research funders should follow these examples and should be encouraging and introducing, at minimum, open access or free-to-read plain text PLS, as a standard submission element, where possible. This is especially important for journals and funders in health and biomedical fields, where research has the potential to impact health policy and clinical practice (Edgell & Rosenberg, 2022).

Enhanced formats
In addition to plain text versions, other visual and digital formats, such as those listed above, offer further significant advantages for improved accessibility and understanding (DeTora et al., 2022).
Using enhanced formats with visual and audio elements allows research information to be catered to different learning styles and accessibility needs, in consideration of health and digital literacy.
This allows content to be tailored towards a more specific target audience and is a crucial consideration when writing for audiences with limited health literacy. Audio and visual formats also have the potential to increase ease of information digestion and reader engagement with a publication (Bredbenner & Simon, 2019;Buljan et al., 2018Buljan et al., , 2020Chapman et al., 2019;Gardner et al., 2019;Huang et al., 2018;Martinez Silvagnoli et al., 2022;Stones et al., 2022). Many publishers and journals are increasingly offering these formats, but some are accepting enhanced formats only if plain text PLS have also been submitted (e.g., Taylor & Francis journals). We therefore strongly encourage publishers and journals to consider offering these additional enhanced formats. One novel approach to enhanced formats in use is Plain Language Summary of Publication (PLSP) articles.

WHAT ARE PLAIN LANGUAGE SUMMARY OF PUBLICATION ARTICLES?
PLSP articles were developed and pioneered by Future Science Group in 2020 (Dormer & Walker, 2020;Tap, 2020). PLSPs follow very similar principles to PLS that accompany peer-reviewed journal publication, but are distinct in that they are standalone manuscripts in their own right and incorporate enhanced formats. PLSPs are peer-reviewed plain language manuscripts that summarize previously published primary publications and are considered acceptable secondary publications according to the International Committee of Medical Journal Editors (ICMJE) recommendations on overlapping publications (Dormer & Walker, 2020;International Committee of Medical Journal Editors, 2022).
Offering plain language content as standalone peer-reviewed articles published in a journal allows the PLSP to be citable in its own right, with each PLSP assigned a unique digital object identifier (DOI) directly referencing the plain language content rather than the original scientific content, which has implications for improved discoverability (Dormer & Walker, 2020). Offering plain language content in a secondary publication rather than (or in addition to) an accompanying summary also means the scope of the content and messaging is not as limited nor needs to so stringently mirror the scientific content. In the case of many PLSPs, this has allowed the scope to expand to include the patient perspective. This may be written as a discrete section of the publication, or it could be woven throughout to incorporate the patient voice into the article narrative, and PLSPs have typically included patient authors (Dormer & Walker, 2020;Fizazi et al., 2021;Wong et al., 2022). The standalone aspect of PLSPs also adds further benefits over and distinctions from PLS in that they are typically much longer (e.g., around 8-10 pages), creating space for additional content such as the patient perspective or room for further details to explain scientific nuance. Also notably, PLSPs are typeset with graphics and visuals by default, for enhanced engagement and accessibility.

THE IMPORTANCE OF PLAIN LANGUAGE
The COVID-19 pandemic has shone a light on both the appetite for research information among a broader audience and the need for data and research information to be accessible and understandable, irrevocably changing the publishing landscape (Brinton, 2021). But, making data accessible is not a new concept. Florence Nightingale famously saw the need to simplify the complex and made strides in novel data visualization techniques with her rose diagram, intended to present statistics in an engaging and accessible medium to attract a greater breadth of readers.
Her efforts ultimately led to reform in health and sanitation policy in Victorian Britain (Andrews, 2022). However, since the days of Florence Nightingale's data storytelling, the language in scientific articles has become increasingly complex and less readable (Plaven-Sigray et al., 2017). PLS, on the other hand, are much easier to read than scientific abstracts (Stricker et al., 2020). PLS are also growing in uptake and popularity (Carvalho et al., 2019;Gattrell et al., 2022;Havran & Hill, 2019;McCormick et al., 2022); anecdotally, our experience has been of authors increasingly wanting to submit to journals that are known to offer plain language options. We also know the public want access to science and research information (3M, 2022). Writing in plain language improves readability and the ability to readily digest information for all readers, regardless of professional or stakeholder background (Loranger, 2017;Oppenheimer, 2005; Fig. 1). In fact, the submission guidelines for the very journal that this article is published in, Learned Publishing, request authors to 'use short sentences, first person, active voice. Avoid over-long paragraphs and use headings to break up the text'. These are all core principles of plain language writing, and are indicative of the journal's recognition of the benefits of plain language to experts and non-experts alike (Association of Learned & Professional Society Publishers, 2022). Writing in plain language also helps to ensure information is communicated accurately and comprehensibly, helping to prevent information overload Kerwer, Stoll, et al., 2021). This has proved especially important in helping to counter the 'infodemic' of COVID-19 pandemic information (Zarocostas, 2020).

THE VALUE AND IMPACT OF PLS AND PLSPs FOR ENABLING DIVERSITY, EQUITY, INCLUSION AND ACCESSIBILITY
Diversity PLS and PLSPs are intended to diversify readership of research by enabling a wider breadth of stakeholders and audiences to engage with content Lobban, Gardner, et al., 2022;Rosenberg et al., 2021) (Fig. 2). Authorship is also diversified by inviting patient authors to collaborate on publications, as is typically done in PLSPs . In the journal of Research Involvement and Engagement, where PLS are required for every submission, 40% of publications include patient or public contributor authors (Stephens, 2022). Future research could help provide more quantitative evidence in regard to diversity, including any trends over time as PLS and PLSPs become more commonplace.
Equity PLS and PLSPs address information equity (along with other key drivers such as openness and discoverability) by helping to bridge the information gap between specialist professionals and other stakeholders, regardless of background or level of experience. When research findings and evidence-particularly those with implications for health and policy-are shared openly and accessibly, different stakeholders can begin to engage across divides on a more equitable platform (Rosenberg, 2022). PLS also represent an opportunity to demonstrate honesty and transparency in research (Maurer et al., 2021). This is a crucial approach, particularly considering that public trust in pharmaceutical companies and private research institutions-which fund a great deal of biomedical research-is relatively low, though it has increased during the pandemic (Gallup, 2020;Ipsos Mori, 2016). Additionally, plain language is proposed to address social inequity by reducing the cognitive burden, better allowing populations experiencing stress-such as under-represented and historically excluded populations-to engage and participate (Cheung, 2017). In the clinic, PLS and PLSPs can facilitate more equitable discussions and dialogue between stakeholders and may better enable evidence-based shared decision-making with patients (Harvey et al., 2020;NHS England and NHS Improvement, 2019).
Part of enabling this is recognizing the benefits that plain language provides to stakeholders at both ends of the shared decision-making dialogue. PLS not only aid easier digestion of research, they also provide a scientifically accurate, plain language tool for explaining novel concepts to patients. To quantify this benefit, 71% of 66 surveyed clinicians in one study rated PLS as 'very' or 'extremely useful', ahead of both infographics and videos. Of these respondents, 43% indicated they used PLS with patients and 17% referred patients to the PLS online . Elsewhere, 46% of 90 surveyed neurologists rated PLS as 'valuable' and 60% would use PLS with their patients, noting that PLS streamline dialogue (Pushparajah et al., 2018). Further, from a cohort of 58 surveyed oncologists and genetic counsellors, 57% indicated they would use plain language guides with patients and 65% would share with colleagues; overall perceived acceptability and utility for informing patient communications was high (van der Giessen et al., 2021).

Inclusion
Information equity creates a more inclusive environment (Myers & Martin, 2021). In addition to the increased breadth of stakeholders, PLS and PLSPs have the potential to promote inclusion by bringing typically under-represented and historically excluded stakeholders, such as those from marginalized communities, into the overall process. This is often in partnership with established stakeholders, for example, patient authorship, which ties in to diversity. The role of PLS in including under-represented and historically excluded voices has been highlighted in a commitment from SAGE Publishing, particularly in relation to the social sciences and journals with subject matter relating to diversity, equity, inclusion and accessibility (DEIA; Keating & Conroy, 2022). PLS and PLSPs can enable patient involvement in research activities, which may be essential for researchers with patient and public involvement (PPI) funding requirements for research grants (Lobban et al., 2018), boosting inclusivity through collaboration and engagement (Rahman et al., 2022). Plain language in the form of summaries of information for patients (SIPs) that accompany health technology assessment submissions are beneficial for patients and patient advocacy groups in understanding medicines in the context of health economic and research outcomes (Cook et al., 2021). SIPs can also support meaningful involvement of patients and patient advocacy groups in this key stage of the drug access decision-making process (Cook et al., 2021).

Accessibility
The value and impact of PLS and PLSPs in enabling accessibility is twofold because it encompasses both accessibility in terms of meeting the access needs of users-that is, health literacy and disability accessibility requirements-and accessibility in terms of access to information.

Access needs of users
The use of accessible language and formats in PLS and PLSPs directly addresses the problem of health literacy. This ability to understand and act on health information is the strongest correlate of poor health (National Voices, 2017). To put the prevalence of low health literacy into context, over 60% of UK adults may not be able to understand and act upon basic health information (Rowlands et al., 2015); nearly 50% of adults from a selection of European countries may have problematic or insufficient health literacy (Sorensen et al., 2015); and up to 90% of US adults may not be able to effectively use health information from community sources, with only 12% demonstrating proficient health literacy  be considered to ensure content meets the needs of users across the spectrum of disabilities and sensory conditions, and to afford all users 'the opportunity to acquire the same information', and in this way ties in to information equity (U.S. Department of Education: Office for Civil Rights, 2013;Pun, 2016).

Access to information
The use of PLS carries the potential to disseminate the news and impact of novel research findings faster by allowing science media or policy and governance professionals to engage with content more readily (Edgell & Rosenberg, 2022). Ultimately, PLS can improve the reach and impact of publications. In one analysis of article metrics, 62% of articles that included plain language summaries were accessed significantly more often than those without (Winter et al., 2022), and the American Geophysical Union reports that publications that include PLS in their journals 'have a higher average number of downloads, a higher average number of citations, and higher average Altmetric scores than those without.' (Halprin, 2021).
Moreover, patients, their caregivers and support networks, as well as expert patients, patient advocates, and patient organizations and advocacy groups are key audiences for PLS in the clinical context. Timely access to research findings and an accessible route into the scientific literature is particularly important for rare disease communities, where patients frequently need to be experts in their own diseases and advocate for healthcare decisions in a shared and equitable manner with healthcare professionals and clinicians, some of whom may be hearing of the rare disease for the first time (Thurtle et al., 2018). Among 74 surveyed patients with a chronic disease, scientific articles were rated the third most important source of online health-related information, behind general internet searches and patient-specific websites, and PLS were considered to be knowledge-sharing tools (Pushparajah et al., 2018). In another study, 31% of 35 surveyed patients with ataxia and their carers indicated they used scientific journal websites to read about ataxia online. Further, 65% reported knowing where to find the scientific literature online, but only 32% found the content easy to understand, and 49% were familiar with PLS (Sheard et al., 2019). Anecdotally, we have observed the use of PLSPs by patients and patient organizations on Twitter and Facebook, reflecting their need to share understandable information with their network. This is evidenced via social media listening using the Altmetrics tool, with one example achieving an Altmetric Attention Score of 70 (Modi, 2021).
Clearly, as scientific communications professionals, we have a responsibility to remove barriers to accessing health information by providing novel research findings in formats and languages according to end-user needs (Procter et al., 2018). PLS and PLSPs are thus an appropriate and resource-efficient step for implementing accessibility in publications. This includes practicing good digital accessibility principles and ensuring content is finan-

CHALLENGES OF DEVELOPING PLS AND PLSPs AND LESSONS LEARNED
Despite demonstrable value and a clear need for PLS and PLSPs, several challenges remain, largely relating to a need for improved  (Griffiths et al., 2022).

Regulatory Lay Summaries Publication-associated PLS Standalone PLSPs
Purpose and audience Mandated summaries of clinical study reports for study participants (typically a target reading age of around 9-13 years) Brief jargon-free summaries, primarily of peer-reviewed publications, for broad non-specialist readers (typically a target reading age of around 14-18 years)  (Griffiths et al., 2022). To help address this challenge, we believe professional associations and societies with involvement in PLS discussions should collaborate on further establishing the growing consensus on terminology for these plain language documents.
A further challenge is the relatively low uptake of PLS . In 2021, the yearly prevalence of PLS indexed on PubMed was 929.1 per million articles . This low uptake is particularly evident among the typically prestigious high tier, high impact factor medical journals. Traditionally, these types of journals have focused on an expert audience, and even though PLS benefit these expert readers, it is important to also recognize that audiences seeking to access novel research findings are diversifying. We believe improved education and awareness are therefore needed to encourage journals to innovate and adapt to a changing scholarly publishing landscape.
Ensuring quality of PLS that follow health literacy best practices and meet end-user needs is also a challenge. Within the pharmaceutical industry, the use of professional medical writing support is associated with higher quality, compliant publications (Gattrell et al., 2016). Many medical writing agencies have dedicated plain language writing teams, trained to deliver and ensure quality, with the ability to consult and advise on developing PLS.
There is also a wealth of training materials and toolkits for learning to write in plain language available for aspiring PLS authors, such as those from the Patient Information Forum and Patient Focused Medicines Development, as well as recommendations and frameworks to guide PLS development Lobban, Gardner, et al., 2022;Rosenberg et al., 2021). Readability metrics, which assign a numerical reading age or level to a piece of text to indicate how understandable it is, can be used to help quantify quality (Grabeel et al., 2018). However, it should be noted that readability metrics can be easily skewed, such as by the inclusion of long drug and disease names, and should not be relied upon as a definitive goal; instead, user-testing with target audience representatives is a better method of PLS quality assurance. Finally, one of the biggest challenges of PLS and PLSPs is discoverability. Currently, the location of PLS in relation to the scientific manuscript is a key driver of whether or not it is discovered and read by readers. Tagging PLS on PubMed and ensuring they are free to read both go a long way in improving discoverability, but not far enough when considering that not all stakeholders may use PubMed. We believe an easily discoverable, accessible, dedicated cross-publisher PLS repository is needed.
Such a repository would need to match the functionality of PubMed while being designed in line with health and digital literacy best practices and according to end-user needs, to ensure that PLS are discoverable by target audiences.

CONCLUSIONS
PLS and PLSPs carry significant implications for improving DEIA in scholarly publishing by enabling information equity. Though many challenges remain in upscaling infrastructure and quality, PLS are already a resource-efficient, timely step towards the democratization of novel research findings that most authors, research funders and publishers can action now. If you are an author, consider drafting PLS or working with medical writing professionals or journal editors to do so, and consider publishing with journals known to accept PLS. If you are a research funder, consider encouraging researchers and grantees to draft and submit PLS in their published research, or perhaps even requiring them to do so. If you are a journal editor or publisher who already offers PLS options, consider offering enhanced formats, or perhaps even requiring PLS for submission, and consider ensuring your PLS options and requirements are explicitly outlined in author submission guidelines. If you do not offer PLS options yet, consider taking steps to do so by working with other publishers who have an established PLS process to learn from their experiences and best practices for publishing PLS. Ultimately, if you are anyone with an interest in making research and scholarly publishing more diverse, equitable, inclusive and accessible, we believe that you should be an advocate for PLS.

AUTHOR CONTRIBUTIONS
All authors contributed to the drafting, development and final approval of the work equally; all authors agree to be accountable for all aspects of the work. This work represents the opinions of the authors and not of their respective affiliations.