The Living Systematic Review: An Answer to Knowledge Translation?

Note: An edited version of this post has been featured on MedPage TodayAs much as it is may be difficult to ignore the fact that traditional systematic reviews and meta-analyses are full of flaws, they have become the bread and butter for not only the purposes of referencing, but also the very basis of why most of us clinicians practice the way we that we do. It becomes very easy to state, “In a meta-analysis conducted by So-and-So, it was found that Intervention X was associated with Outcome Y” without even pulling the articles included in the citations of the meta-analysis and reading the articles in length as a skeptic to formulate our own opinions about the outcomes associated with said intervention.
In addition, let us not forget an essential component of these types of publications – the fact that a large window of time that elapses between publication of the original articles and publication of the meta-analysis or systematic review that incorporates these original articles. The truth of the matter is that articles that may blow our minds today may not have the same sort of impact six months, one year, three years, five years, and ten years down the line (and vice versa). In addition, you may find several meta-analyses and systematic reviews may no longer be relevant by the time of publication as the results of a ground-breaking trial may have been released to the general public at nearly the same time, or the fact that a more recent systematic review or meta-analysis was published that you may have been unaware of in the first place.
Needless to say, the authors of such reviews and analyses spend much time synthesizing and writing these articles that their efforts should by no means go unnoticed. Say you have your topic designated with your search terms and you conduct your search, pulling all the available literature and reviewing the literature at length. Three months pass, the manuscript is nearly complete, and you conduct the search again, only this time, you find three additional case reports published on the very topic that you decide to incorporate in your review. After all, should it not be as up to date and as comprehensive as possible? The manuscript is finally complete and you submit it to your top journal of choice for review. Several weeks have passed and while you are awaiting comments back from the reviewers, you decide to go ahead and do a brief search to see if anything has been published on said topic that you have written about. Lo and behold, a systematic review has been just published on the same exact topic. You think to yourself, “Son of a gun…well, maybe the focus of my manuscript is a little bit different, so hopefully it will fly.” You read the systematic review and the authors have not only taken a pretty similar stance related to the topic, but their review incorporates many of the same articles that you have included in your manuscript. You feel deflated, discouraged, and more than a little PO’d about it, but what can you do? What is done is done, and there is no turning back.
Now let us approach this from the view point of the reader who may find it somewhat comical to read such systematic reviews or meta-analyses that are published at nearly the same time. Case in point, a few months ago, I decided to brush up on my knowledge related to the role of glucarpidase in the management of methotrexate toxicity. Doing a simple PubMed search using the words “glucarpidase” and “methotrexate”, I came across three review articles published this past spring alone in different pharmacy journals:
Date of Publication
Efficacy of glucarpidase (carboxypeptidase g2) in patients with acute kidney injury after high-dose methotrexate therapy
May 2014 [Epub October 2013]
Glucarpidase for the management of elevated methotrexate levels in patients with impaired renal function
American Journal of Health-System Pharmacy
May 2014
Glucarpidase intervention for delayed methotrexate clearance
Annals of Pharmacotherapy
Epub April 2014
I get it, I really do- lag time between time of writing to publication and all that. But do I really need three different systematic reviews on the same exact topic with essentially the same conclusions drawn on the topic that are published at nearly the same time to boot? It would make so much more sense to have one central system that allows for these and other future publications on the topic to be reviewed by a designated set of authors who have no bias related to the topic made available in real time to the general public.
Enter the living systematic review.
No, it is not a breathing entity as the name implies. This is a concept that was interestingly first written about by several contributors to the Cochrane Collaboration (1). The authors cite several limitations of the accuracy and relevance of the traditional systematic review and propose this idea as a way of overcoming some of these challenges. Here is their definition and vision for the living systematic review:
“Living systematic reviews are high quality, up-to-date online summaries of health research, updated as new research becomes available, and enabled by improved production efficiency and adherence to the norms of scholarly communication.” (1)

The authors propose that in order for such a systematic review to thrive (literally and figuratively), essential components of this process include adaptation of such a continuous work process on the part of the contributors to the review; minimization of repeated analyses of data that have previously reviewed elsewhere to prevent overinflation and redundancies of reported outcomes; the utilization of automated technologies to enhance the processes involved in such systematic reviews, including the protocol for review, the search itself, and data extraction; and engagement and participation of the process with a large number of contributors, somewhat similar to crowdsourcing for information.

This very concept of the living systematic review was called upon as a welcome opportunity in a recent editorial published by JAMA Pediatrics evaluating the vastly different results of two recently published trials on the role of nebulized hypertonic saline in the management of bronchiolitis (2). The authors of the editorial state that an update to the currently available Cochrane systematic review that was recently released in 2013 on this topic (3) will require incorporation of these two trials to help guide clinicians with the best course of action to take when managing such patients, and propose that perhaps such a living systematic review will help narrow the gap in evidence-based practices.
Wait a minute…much of these proposals for the living systematic review sound a bit familiar to me. I hear whispers that were once long-standing echoes that are now realities of the activities of us folks involved in the movement of free open access medical education (FOAMed) here. We are doing this already as a means of sharing and disseminating information with a large worldwide community of folks truly invested in this movement for the purposes of enhancing our learning and engagement in the vast world of medicine. Many of us are doing so in the form of blogs and podcasts, and we are analyzing and really breaking down core concepts in medicine and diagnostic and therapeutic interventions alike, including conducting in-depth reviews of recent and long-standing studies that define and impact our clinical practice. At the end of the day, much of our focus of these concepts is for the purposes of both applying these principles to direct patient care and educating future generations of practitioners.
The proposal for the living systematic review seems to me to be a somewhat more formalized approach to defining an aspect of our activities in the world of FOAMed. Given the fact that folks who engage in activities of conducting systematic reviews and meta-analyses on a regular basis are recognizing that change is needed and are proposing that living systematic reviews have a place in the arena of evidence-based medicine in facilitating the narrowing the window of knowledge translation is worthy in and of itself. And I say, bring it.
The Living Systematic Review: An Answer to Knowledge Translation? References:
  1. Elliott JH, Turner T, Clavisi O, et al. Living systematic reviews: an emerging opportunity to narrow the evidence-practice gap. PLoS Med 2014; 11(2):e1001603.
  2. Grewal S, Klassen TP. The tale of 2 trials: disentangling contradictory evidence on hypertonic saline for acute bronchiolitis. JAMA Pediatr 2014; 168(7):607-9.
  3. Zhang L, Mendoza-Sassi RA, Wainwright C, Klassen TP. Nebulised hypertonic saline solution for acute bronchiolitis in infants. Cochrane Database Syst Rev 2013; 7:CD006458.
  4. The Living Systematic Review: An Answer to Knowledge Translation?