In nursing research the literature review is the perfect starting point and an important step in developing a base of knowledge on what exists in the research literature on a topic or question.
What is it?
It is an assessment of relevant research on a particular topic/question. The literature review surveys books, scholarly journal articles, dissertations, conference proceeding and more on a specific topic/question. It provides a historical background and identifies leading scholars in the field.
How is it done?
The author(s) reads all relevant literature on a subject, organizes and synthesizes the findings, and critically evaluates this information. The result is a concise overview of a particular topic/question.
Who uses them?
Literature review articles are intended for specialists in the field and researchers. They are written using technical/professional jargon and are not for the layperson.
What do they provide?
They expose what has been done in research thus avoiding duplication as well as uncovering gaps in the research indicating where further research is needed. They provide an extensive bibliography rather than introductory or selective sources. They provide a level of confidence that important literature is not overlooked while researching a topic/question.
Mann, T. (2015). The Oxford guide to library research. New York: Oxford University Press.
American Association of Critical Care Nurses evidence-based care pyramid. See the chart below for examples of how the levels of evidence appear in different kinds of studies.
| Level of Evidence | Type of Study | Definitions | Strengths |
|---|---|---|---|
| A | Meta-analysis | A technique for quantitatively integrating the results of multiple similar studies addressing the same research question. | Statistical summary of articles of the same topic of research; process of using quantitative methods to summarize the results from multiple studies. |
| A C |
Systematic review If quantitative study If qualitative study |
A rigorous synthesis of research findings on a particular research question obtained by using systematic sampling and data collection procedures and a formal protocol. | Review by experts in the field of all the research on a topic, who rigorously appraise the studies and offer the conclusion to support an intervention or not |
| B | Randomized controlled trial | A full experimental test of an intervention, involving random assignment to treatment groups | True experimental study in which the researchers are often blinded to which patients or participants are receiving an intervention; the strongest design for examining the cause and effect of an intervention; reduces bias |
| C | Cohort study | A nonexperimental design in which a group of people (a cohort) is followed over time to study outcomes | Prospective longitudinal study that examines 2 groups of patients or participants (the cohort) |
| C | Case-controlled study | A nonexperimental research design involving the comparison of a case and a matched control* | Longitudinal study that retrospectively compares characteristics of an individual who has a certain type of condition that may not be very common; often used to identify variables that may predict the etiology or the course of a disease |
| C | Integrative review | Reviews of qualitative studies, often taking the form of metasyntheses, which are rich sources for evidence-based practice | Compilation of studies that are reviewed and summarized; may incorporate research and nonresearch articles |
| C | Metasynthesis | Interpretive translations produced from the integration or comparison of findings from qualitative studies on a specific topic | Compilation of qualitative studies looking for the common themes among similar research studies |
| C | Qualitative research | Investigation of phenomena, typically in an in-depth, holistic fashion, through the collection of rich narrative materials by using a flexible research design | Method to develop a greater understanding of a topic using many different methods such as observation or interview |
* In an experimental design, the researcher controls the variable by randomly assigning patients or participants to different treatment conditions. In nonexperimental studies, the researcher collects data without introducing intervention (also called observational).