Young GI angle: Why and how to write a good review article.

Abstract

Review articles aim to give an overview of the current scientific knowledge on a specific topic and are an important element of evidence-based medicine. Technically, review articles do not generate new data, but rather identify, structure, evaluate and summarize the evidence of existing primary research studies.1 While narrative review articles usually apply a less stringent methodology and present a broader scope of a topic, systematic reviews aim to answer precisely a specific scientific question by synthesizing the available evidence qualitatively and, whenever possible, quantitatively as meta-analyses, which requires profound methodological knowledge and skills in statistics. Narrative and systematic elements (with or without meta-analysis) can also be combined in one article.2 In any case, review articles tend to be of high quality, basically for two reasons: first, since they reach out to a broader audience and their visibility is more long-lasting compared with fast-moving original studies, authors and publishers want to ensure they do not lose their reputation. And second, they are usually written by either experts of a certain field or by researchers who are specifically dedicated to, and have a high level of expertise in, conducting systematic reviews and meta-analyses. At the same time, writing a review article comes with a considerable burden of responsibility because they shape future research.1 For instance, where evidence is scarce, review articles can create awareness of an unmet need to start up new projects. In other fields, evidence can be so abundant that it has become nearly impossible for researchers to read and appraise all available studies, and review articles are a welcomed source to understand current evidence with a reasonable effort of time. It is obvious that before you consider writing a review article you need to understand your subject both deeply and broadly, which is rarely the case for young researchers or clinicians who might just have started to subspecialize in a certain field. In addition, allocating, reading and evaluating the available evidence from various sources such as MEDLINE, EMBASE, Cochrane library, and so on, can be very time consuming, and time is usually scarce in the life of a young researcher who in parallel works on the wards, deals with night shifts or other research projects, and so forth. This is why most newcomers start their careers with easier types of articles such as case studies, or aspire to gain scientific credits by performing and publishing original studies. Young professionals might also be intimidated by the more stringent review process, which in the case of review articles usually includes at least four peer reviewers, and these tend to be very critical. Because of the need to deeply understand a topic, and their potentially important impact on future research or even on clinical practice, most review articles are written by recognized experts. In fact, it is rather unlikely that a publisher would accept a review article that was not submitted by an expert, or at least an author with some kind of seniority. Moreover, in many cases it is the publisher who invites an expert to write about a certain topic. However, in this case it is frequent that the senior will ask a younger group member to do the hard work. Despite all the obstacles, there are important reasons why young researchers should engage in writing review articles. It is true that when it comes to career promotions or gaining research funding, oftentimes publications of original work in prestigious journals have the heaviest weight. However, high-quality review articles are usually published in high-impact journals too, and contribute substantially to the researcher’s prestige and visibility as they are read by a broad audience and are frequently cited.1, 3 For the seniors it is also evidence that a young colleague is capable of diving into and managing a complex topic that requires a high degree of motivation and dedication. But most importantly, writing a review is a great opportunity to gain comprehensive and profound knowledge which can be the starting point for a new line of research and/or the introduction of a PhD thesis. From the viewpoint of the scientific community, it cannot be appreciated enough how fulfilling and satisfying it is for a scientist to have contributed to guiding future research and inspiring new projects. And lastly, a good review article may be a marker that starts to position you as an expert in your field. There are plenty of resources and readings that can help you through the process of preparing and writing a good review article,1-4 so I will not go into detail here but rather highlight some of the most important lessons I learned when I wrote my first review article. Even before you start, the most important thing is your attitude. Obviously, the extent of your review will depend on the topic or the amount of available evidence, but in general I recommend that you do not expect quick results; be patient and carry on your work continuously and with dedication. If this is not a review that you or your principal investigator have been invited by a journal to prepare, the next step is to define the aim and purpose of your review and to formulate an answerable question. In most cases, this will determine what subtype of review article you will be approaching. For instance, if you want to summarize everything currently known about a certain pathology, or how treatment options or technologies have evolved over time, then a narrative review is suitable. By contrast, if you want to appraise all the evidence on a specific intervention for a specific disease, a systematic review is the right choice, eventually combined with a meta-analysis if the original data allow this. For systematic reviews, ‘PICO’ is an acronym that summarizes the framework you will need to formulate your scientific question and organize your literature research: what kind of p ersons (or patients) undergo which kind of study i ntervention (i.e. treatment or diagnostic procedure), are c ompared with what other kind of standard procedure, and what o utcomes are we interested in?5 In this phase it is advisable to do a first scoping of your question in order to see how much evidence is actually out there. This will help you to refine or extend your question and search strategy. It is not uncommon to retrieve your final search results after several cycles of search and re-search.3 Keep in mind that although your review article has of course to reflect up-to-date research, don’t forget to also consider older papers. In any case, I strongly recommend that you are as systematic as possible, and to almost obsessively document your search strategies, your search results and the main findings and conclusions of the papers you want to include in your review article, because otherwise it is quite easy to lose track when you are dealing with hundreds of papers. Compared with original articles, it is more common for review articles to be written by a smaller number of authors, though they usually contribute more equally to analysis and writing. For instance, it is convenient to divide a large narrative review into sub-chapters and then distribute them among the authors. In a systematic review, it is a sign of high quality when both literature research and quantitative analyses are performed by at least two researchers independently and in a blinded way, and when results are then compared with each other, because this reduces substantially sources of selection bias.4 As good teamwork is decisive for getting a coherent narrative and results, make sure that you arrange regular meetings. These are not only important to discuss relevant concepts and results, but will also help you to push the project forward and not to lose time. As I mentioned before, writing review articles requires a high level of expertise which of course you will gain during the process, but it is indispensable that you have at least one mentor on your side who is well-known in the field and serves as senior author, enhancing considerably your chances of being accepted by the journal. In order to become familiar with the methodology and the prevailing language of review articles, a good idea is to read at least two to three reviews of a similar topic, and/or that are published in the journal you are planning to submit to. When you have your data together, the PRISMA guidelines are of immeasurable value to summarize the literature critically, appraise the findings and results, identify biases and finally draw useful conclusions.6 Be aware that simply listing previous data will not provide any additional information to the scientific community, and the manuscript will likely be rejected. Hence, focus on finding gaps of knowledge that could justify new projects, consistent results that potentially could change current paradigms or clinical management, contradictory findings and how you interpret them to guide subsequent studies, and/or identifying biases, limitations and weaknesses and how future studies could be designed to avoid them. Cochrane is a London-based international charity organization with more than 30,000 volunteer experts who are committed to generating high-quality, relevant and accessible systematic reviews, and offers online training modules and webinars about evidence-based medicine and systematic reviews.7, 8 The course Introduction to Systematic Review and Meta-Analysis offered by the Johns Hopkins University is also highly recommended, and you can access it for free on the online learning platform Coursera. 9 As a tool, the PRISMA statement provides guidance to improve and standardize the reporting of systematic reviews and meta-analyses, and an increasing number of journals have incorporated the PRISMA statement into their instructions to authors. On the PRISMA website you can download the four-phase flow diagram, the 27-item checklist and further tips that will help you to make your review perfect.10 Engaging in review articles is an excellent opportunity for young talents to expand their in-depth knowledge of a certain topic and to foster a wide range of methodological skills in science, from critical reading to advanced statistics and effective writing. The task might seem unmanageable initially, but tools, checklists, courses and plenty of advice from seniors are very supportive, and remember that you only grow outside of your comfort zone. After all, being the author of a distinguished and highly cited review article will certainly be one of the key stones to establishing yourself as an expert. 1 https://training.cochrane.org/essentials 2 https://training.cochrane.org/ 3 https://www.coursera.org/learn/systematic 4 http://www.prisma-statement.org This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.