Instructions for Performing a Literature Review
Umbrella reviews, a unique type of literature review, have gained significant attention in the research community. Unlike traditional literature reviews, umbrella reviews aggregate the results of multiple systematic reviews and meta-analyses, providing a consolidated and comprehensive synthesis of the results.
The main purpose of an umbrella review is to manage the overwhelming amount of individual reviews and meta-analyses, especially in fields where multiple interventions or competing approaches exist. Umbrella reviews are most beneficial when there is already a substantial body of systematic reviews and meta-analyses on a broad topic.
Umbrella reviews offer several advantages. They address broad questions by synthesising evidence from diverse reviews, going beyond individual meta-analyses. By doing so, they help identify inconsistencies, heterogeneity, and risk of bias across studies, improving the assessment of the credibility and robustness of the evidence base.
Umbrella reviews save time for policymakers, clinicians, and researchers who need a single, accessible summary across many interventions or topics without reading multiple individual reviews. They support guideline development and informed decision-making by providing a clearer panorama of what is known and where knowledge gaps or controversies remain.
The umbrella review process is a systematic method, developed by Baumeister and Leary (1997) and Higgins et al. (2019). A detailed protocol is created for the umbrella review, including inclusion and exclusion criteria, search strategy, and methods for data extraction and analysis. Data extraction involves using a standardized form to extract data from the selected studies.
The report and interpretation of results in an umbrella review involve writing a comprehensive report and interpreting results in the context of existing knowledge. Umbrella-Reviews are comprehensive overviews that summarise knowledge from multiple systematic overviews and meta-analyses.
The critical appraisal of the included reviews in an umbrella review involves assessing their methodological quality using tools such as the PRISMA statement and the JBI critical appraisal tool. The synthesis of findings in an umbrella review involves summarising data from the selected reviews and presenting them in a clear and concise manner.
Umbrella-Reviews are particularly useful in fields with rapidly evolving research landscapes, such as biomedical literature, where the number of systematic reviews and meta-analyses can become overwhelming. They integrate results from various systematic reviews published on the same topic, helping to identify consistent patterns, highlight differences, and provide a more nuanced understanding of the evidence.
Overviews are valuable in fields such as health, education, and social sciences for informing strategies and practices, identifying research gaps, and supporting grant applications. A free trial version of software is available to assist in the conduct of an umbrella review, from literature search to analysis.
The first step in conducting an umbrella review is defining the scope and objectives of the review. The literature search for an umbrella review involves finding existing systematic reviews and meta-analyses from various databases. The screening and selection of studies for an umbrella review involves reviewing studies against predefined criteria for relevance and selecting those that meet the inclusion criteria.
Umbrella-Reviews are indispensable in fields such as biomedical literature, medical research, psychology, and genetics. They help researchers and decision-makers keep up with the latest findings and make informed decisions based on the most comprehensive and up-to-date evidence available. In essence, umbrella reviews are most advantageous when the existing literature is already well covered by systematic reviews/meta-analyses, and when stakeholders require a clear, overarching synthesis to guide practice, policy, or further research.
The process of conducting an umbrella review is beneficial for education and self-development, particularly in online learning environments, as it offers a synthesized and comprehensive understanding of the results from multiple systematic reviews and meta-analyses, saving time and providing a clear panorama of the current knowledge on a broad topic.
Umbrella reviews contribute to research by identifying inconsistencies, heterogeneity, and risk of bias across studies, improving the assessment of the credibility and robustness of the evidence base, which is crucial for informed decision-making and guideline development in various fields, including education and self-development.
