An Overview of the Methodology and Reporting Standards for Umbrella Reviews

What are Umbrella Reviews?

Definition

Essentially, Umbrella reviews are a cluster of existing systematic reviews on a shared topic. They are called by many names, overview of reviews being the most common one. Umbrella reviews are overarching in nature as they aggregate the findings from different reviews and address the specific questions. Each of the umbrella reviews focuses on a broad condition or problem in which there are more than two or at least two potential interventions and brings out the reviews that address these potential interventions and their results.

The past few decades have seen a phenomenal rise in publications by researchers. This has increased the need for evidence synthesis so that the knowledge about specific topics can be collated and summarized. This practice helps in creating substantive evidence for policy makers, clinicians, researchers, educators which is useful across a variety of issues.

A lot of literature review techniques are available and all of them have their own methods. Some of the common literature review techniques that are used by researchers are, systematic review, scoping review, Integrative, Narrative, and the qualitative methodologies are the most common to see. Reviews are being used extensively as a secondary data source for they help in summarizing huge volumes of published evidence in some of the fields of research.

There is plethora of primary and secondary sources that are available. This has made the task of researchers and readers difficult, where they must spend a vast amount of time sourcing, collating, and analyzing the compiled summaries into meaningful conclusions. The umbrella methodology comes to rescue here. It overcomes the problem by synthesizing findings from so many sources to report on a single source of research.

Background of Umbrella Reviews

There is an increase in the number of publications using the umbrella technique. As the name is suggestive, umbrella technique brings the literature reviews under one umbrella or canopy. There are multiple names for this technique and different researchers call it by different names. The method is called review of reviews, overview of reviews etc. The technique is extremely robust and considered useful for creating knowledge that is reliable on well researched topics.

During the initial years, after the inception of this technique, umbrella reviews were more focused on systematic reviews and meta-analysis. As the approach got more and more popular, the focus shifted towards incorporating studies and reviews of various designs that were dependent on umbrella review question and the topic that was under investigation.

 Purpose and application of Umbrella Review

There is diverse purpose of umbrella review. One major purpose of this technique is to give the researcher or reader a succinct report of the available secondary evidence on the topic of research. The analyzed data and the reporting of primary evidence are collated. This prevents repetitive analysis. Further they are synthesized and interpreted. This method produces timely evidence in a brief span of time in comparison to traditional systematic reviews of primary studies. Another important use and purpose of this technique is that it alleviates the reader from feeling anxious when they get a huge volume of literature or evidence on the topic of research. This becomes all the more overwhelming when they have conflicting conclusion and different findings. The umbrellas technique dilutes this problem thus easing out the task to a great extent.

Furthermore, umbrella review also validates the quality of the evidence, the level of the evidence and the publication bias in the experimental designs. The researcher automatically starts feeling more confident as he realizes the technique is extremely reliable and robust. Categorically, this approach serves as an extremely reliable, fair, transparent source to inform evidence-based decision making. The use is seen primarily in the health care industry where its application is found in abundance.

In the healthcare sector, many nursing topics are seen getting addressed as umbrella reviews. Nursing handovers, patient security and safety, the risk factors of bypass surgery, postpartum depression amongst new mothers, to name a few.

Process for conducting Umbrella Reviews

Let us look at the list of recommended steps that can help to methodically plan and conduct the umbrella review.

1. Understand and explain the reasoning to use Umbrella review to all co-authors: As a researcher, first you need to get convinced on the clear need to use Umbrella Review technique in your research, further on, if you have co-authors you must justify to them the reason for which you are using this technique. Some of the kind of topic where umbrella review works well are

• Controversial topic
• Topics that can be biased
• Topics that have a vast ocean of reviews available

2. Design the layout for the study and if needed register the review protocol: Designing the study layout is very important to methodically conduct the research. PICO approach can be used for this purpose. PICO stands for Population, Intervention, Comparator, Outcome. Fix the title and the research question here. It is better to include the review technique in the title itself, whether you are using umbrella technique or any other. In case you decide to register your review protocol for umbrella technique, you must refer to the umbrella guide for that.
3. Prepare the strategy for search of literature and then conduct the search: Before you start to search for relevant literature, you must have a list of review objectives, even if broadly specified and the inclusion criteria that would address the review questions.  So that you can hit the bull’s eye in selection of literature, you must know the participant type, phenomena of interest, context pr setting and the outcomes of review.
4. List and identify the reviews included: A PRISMA technique can help you to present a flow chart of the search process. From among all co-authors, at least two authors should be at the task of screening the studies and identifying the ones for inclusion.
5. Assess the quality of the methodology of the chosen papers: Two reviewers must independently be at task for taking up quality assessments. Before starting the job, create a quality checklist. You can take help from sources on the internet for creating a checklist, do customize it according to the objectives of your own research and what meets your chosen criteria.
6. Present the extracted review results: Describe the extracted review results. You can see some examples of data extraction tables to get an idea of how to do it.  Narratively summarize the process also bring to highlight the points of interest from individual reviews.
7. Report the findings and evidence summary: Create a succinct but inclusive summary of the chosen reviews. Describe/name the included interventions. Effectively report the synthesized results/outcomes. The graphs, charts, and tables can be used to help readers to better understand the process and methods. They must be used extensively. Summaries the results in a methodical manner.  Techniques such as the word cloud, thematic map or traffic light system could be used.
8. Identify the limitations and benefits of review: Describe the limitations and benefits of the review so that the reader knows well what the best takeaway from the research is.
9. Conclusion: Create a comprehensive summary of the findings and describe the implications for further research.

When to use the Umbrella Review?

Umbrella reviews are best suited as the second stage reviews. Those topics which are already addressed in systematic and/or meta-analysis come here. Umbrella reviews are used fir combining the results for various reviews on a certain topic or question.

After a broad area of study has been split into more focused population and interventions, the umbrella review attempts to impose an overall coherence by putting the precise reviews together. They find great amount of applicability and use within health technology assessments which target to consider all management options and yet may commission separate reviews of an individual treatment with specific outcomes.

Components of an Umbrella Review

There are a few typical characteristics, some strengths and challenges associated with umbrella reviews

Characteristics

• It is essentially a single document that includes evidence from different variety of Cochrane reviews
• It is possible to accomplish an umbrella review if the intervention of interest has been discussed in detail in the review

Key Strengths

Umbrella reviews have some significant contribution to make in the research domain because of their key strengths

• Helps to create a quick overview of the reviews on any specific topic as well as all other relevant reviews that have been conducted on that topic.
• Reviewers in general face the problem of lumping versus splitting. It is a perennial dilemma which means that the reviewer is confused whether the needs of a particular field are best addressed by a broad or focused review.
• Umbrella reviews build upon the foundation of systematic reviews on any given topic. When the topic has been well covered by systematic reviews, it just synthesizes the evidence from all relevant ones to generate a single report which summarizes the current state of knowledge on the topic.
• Umbrella reviews help to bring together many treatment comparisons for the management of a single disease or condition in the health care sector

      Key Weaknesses

Few weaknesses of the umbrella reviews can be

• An umbrella review always needs the pre-condition of existing reviews on the topic to be able to synthesize the outcome and compile.
• The quality of the umbrella review is dependent on the quality and comprehensiveness of the available information in the previous studies.

Systematic Reviews Vs Umbrella Reviews

Many a times readers confuse between systematic reviews and umbrella reviews. There is of course a distinction between the two. One should very clearly know that umbrella review is a synthesis of existing reviews, and it only includes the highest level of evidence, such as systematic reviews or meta-analysis or its likes. It specifically refers to the reviews that puts together the evidence from multiple reviews intone accessible and usable document. Umbrella reviews target on either a broad situation or problem for which the findings or interventions are interventions. The umbrella reviews specifically highlight the different interventions and their results. A systematic review can be the foundation of for an umbrella review and it attempts to bring together the reviews on a particular theme in a systematic manner and with the increase in the number of systematic reviews available, the next most logical thing to do it to provide decision makers in healthcare with the strong evidence they need, which is that the further review of existing reviews has been conducted. The bottom line is, the syntheses of existing systematic reviews are referred to by many names, one of which is umbrella review.

Conclusion

The review of reviews or the umbrella review is proven to have an advantage in reporting evidence that is both convergent as well as divergent and describing what is the unknown.  This is only made possible by synthesizing the evidence from a range of studies that has been informed by different methodologies and overall is a representation of a huge number of participants. The technique isn’t new but is surely emerging in nature to for evidence synthesis methodology that is able to offer timely analysis on research queries.

Depending on the topic of study, if there is a need to conduct umbrella reviews it gives productive results.  But overall, a review of reviews, under all circumstances, contributes significantly to the ever-growing body of scholarly knowledge.

Umbrella reviews are strongly recommended for readers, amateur researchers who feel anxious and overwhelmed with a plethora of literature thar is available on their chosen topic of research. For the policy makers who want to make the right decision which is based on evidence and is not time consuming, the umbrella review technique is a strong recommendation. In situations where the data is conflicting in nature, not transparent, these kinds of reviews work very well.

With the surge in the volume of primary and secondary evidence reports, umbrella review methodology as a scientific tertiary research approach will continue to increase in popularity.