Skip to main content
site header image

Systematic Review Resources: Systematic Reviews vs Other Types of Reviews

This guide is designed to help you get started on a systematic review and provide guidance on a wide variety of resources.

Aim of Subject Guide

This subject guide provides an overview of other types of reviews and how they compare to systematic reviews. Library staff  can help researchers at the UTHealth School of Public Health Library and the Texas Medical Center Library during a systematic review process. This guide focuses on systematic reviews in a Health Sciences setting.

Types of Literature Reviews

There are various types of literature reviews, including

  • Systematic review
  • Meta-analysis
  • Literature Review
  • Scoping review
  • Rapid review
  • Umbrella review
  • Systematized Review

This article describes fourteen different review types and associated methodologies (scroll down to Table 1 on p94/95):

Systematic Review

A systematic review attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question. It uses explicit, systematic methods that are selected with a view to minimizing bias, thus providing more reliable findings from which conclusions can be drawn and decisions made (Antman 1992, Oxman 1993).

The key characteristics of a systematic review are:

  • a clearly stated set of objectives with pre-defined eligibility criteria for studies;
  • an explicit, reproducible methodology;
  • a systematic search that attempts to identify all studies that would meet the eligibility criteria;
  • an assessment of the validity of the findings of the included studies, for example through the assessment of risk of bias; and
  • a systematic presentation, and synthesis, of the characteristics and findings of the included studies.

From Cochrane Handbook, 1.2.2

Meta-Analysis

Many, but not all, systematic reviews contain meta-analyses. Meta-analysis is the use of statistical methods to summarise the results of independent studies. By combining information from all relevant studies, meta-analyses can provide more precise estimates of the effects of health care than those derived from the individual studies included within a review. Meta-analyses also facilitate investigations of the consistency of evidence across studies, and the exploration of differences across studies (Cochrane Handbook, 1.2.2). More information on meta-analyses can be found in Cochrane Handbook, Chapter 9.

meta-analysis goes beyond critique and integration and conducts secondary statistical analyses on the outcomes of similar studies.  It is a systematic review that uses quantitative methods to synthesize and summarize the results.

An advantage of a meta-analysis is the ability to be completely objective in evaluating research findings.  Not all topics, however, have sufficient research evidence to allow a meta-analysis to be conducted.  In that case, an integrative review is an appropriate strategy.  

 

Literature Review

literature review is something most of you have done this at one time or another. As a publication type it is an article or book published after examination of previously published material on a subject. It may be comprehensive to various degrees and the time range of material scrutinized may be broad or narrow, but the reviews most often desired are reviews of the current literature. The textual material examined may be equally broad and can encompass, in medicine specifically, clinical material as well as experimental research or case reports.

State-of-the-art reviews tend to address more current matters. A review of the literature must be differentiated from a HISTORICAL ARTICLE on the same subject, but a review of historical literature is also within the scope of this publication type. The literature review examines published materials which provide an examination of recent or current literature. Review articles can cover a wide range of subject matter at various levels of completeness and comprehensiveness based on analyses of literature that may include research findings. The review may reflect the state of the art. It also includes reviews as a literary form.

An integrative review summarizes past research and draws overall conclusions from the body of literature on a particular topic. The body of literature comprises all studies that address related or identical hypotheses. In a properly executed integrative review, the effects of subjectivity are minimized through carefully applied criteria for evaluation. A well-done integrative review meets the same standards as primary research in regard to clarity, rigor and replication.

At its most basic, narrative reviews are most useful for obtaining a broad perspective on a topic and are often more comparable to a textbook chapter including sections on the physiology and/or epidemiology of a topic. 

When reading and evaluating a narrative review, keep in mind that author's bias may or may not be present.  The labels Narrative Review and Literature Review are often describing the same type of review. 

For scientific purposes, the term Literature Review is the one used most often.

This resource outlines the difference between a systematic review and a literature review:

 

If you think you do not need a systematic review but still need a Literature Review that is exhaustive, but not protocol-driven, librarians can still assist. To begin, fill out the online request form.

Is a Systematic Review for You?

​Data Considerations

  • Do I have a clearly defined clinical question with established inclusion and exclusion criteria?
  • Do I have a team of at least three people assembled?
  • Do I have time to go through as many search results as we might find?
  • Do I have resources to get foreign language articles appropriately translated?
  • Do I have the statistical resources to analyze and pool data?

If you answered “No” to any of the first four questions, a traditional Literature Review will be more appropriate to do.

If you answered “No” to the last question, a meta-analysis will not be an appropriate methodology for your review.

The following further outlines the difference between a "Systematic Review" and a "Literature Review."

 

Scoping Review or (Mapping Review)

"In general, scoping reviews are commonly used for ‘reconnaissance’ – to clarify working definitions and conceptual boundaries of a topic or field. Scoping reviews are therefore particularly useful when a body of literature has not yet been comprehensively reviewed, or exhibits a complex or heterogeneous nature not amenable to a more precise systematic review of the evidence. While scoping reviews may be conducted to determine the value and probable scope of a full systematic review, they may also be undertaken as exercises in and of themselves to summarize and disseminate research findings, to identify research gaps, and to make recommendations for the future research."

From Peters, MD, Godfrey, CM, Khalil, H, McInerney, P, Parker, D & Soares, CB 2015, 'Guidance for conducting systematic scoping reviews', International Journal of Evidence-Based Healthcare, vol. 13, no. 3, pp. 141-146:

Rapid Review

Assessment of what is already known
about a policy or practice issue, by using
systematic review methods to search and
critically appraise existing research
Assessment of what is already known
about a policy or practice issue, by using
systematic review methods to search and
critically appraise existing research

A rapid review is an assessment of what is already known about a policy or practice issue, by using systematic review methods to search and critically appraise existing research. "Rapid reviews have emerged as a streamlined approach to synthesizing evidence in a timely manner -typically for the purpose of informing emergent decisions faced by decision makers in health care settings."

Khangura, S, Konnyu, K, Cushman, R, Grimshaw, J & Moher, D 2012, 'Evidence summaries: The evolution of a rapid review approach', Systematic Reviews, vol. 1, no. 1, p. 10.

Umbrella Review

An Umbrella review is a synthesis of existing reviews, only including the highest level of evidence such as systematic reviews and meta-analyes. It specifically refers to review compiling evidence from multiple reviews into one accessible and usable document. Umbrella reviews focuses on broad condition or problem for which there are competing interventions and highlights reviews that address these interventions and their result.

Methodology paperAromataris, E, Fernandez, R, Godfrey, CM, Holly, C, Khalil, H & Tungpunkom, P 2015, 'Summarizing systematic reviews: Methodological development, conduct and reporting of an umbrella review approach', Int J Evid Based Healthc, vol. 13, no. 3, pp. 132-140.

Systematized Review

A systematized review attempts to include elements of the systematic review process while stopping short of the systematic review. Systematized reviews are typically conducted as a postgraduate student assignment, in recognition that they are not able to draw upon the resources required for a full systematic review (such as two reviewers).

typically conducted as a postgraduate student
assignment, in recognition that they are not able to
draw upon the resources required for a full
systematic review (such as two reviewers).
typically conducted as a postgraduate student
assignment, in recognition that they are not able to
draw upon the resources required for a full
systematic review (such as two reviewers).
typically conducted as a postgraduate student
assignment, in recognition that they are not able to
draw upon the resources required for a full
systematic review (such as two reviewers).
typically conducted as a postgraduate student
assignment, in recognition that they are not able to
draw upon the resources required for a full
systematic review (such as two reviewers).