Review of literature

Review of literature
A research literature review is a written summary of the state of existing knowledge on a research problem. It helps the researches to seek knowledge on a topic of interest and synthesize evidence based information to gain knowledge and improve nursing practice. 

The purposes of review of literature among researchers are:
It helps to;
-assemble knowledge on a topic
-identification of relevant research problem
-refine research questions
-gain insight to what is known and not known about an area of inquiry
-determine gaps in a body of research
-determine he need of replication of many nursing studies
- identify the suitable methodology to carry out a study
-interpret study findings and in developing implications and recommendations
The research reviews also included in research proposals, documents that describe what a researcher is planning to study, how the study will be conducted and how much will cost to complete the study. 

The purposes of review of literature among non researchers
The nurses involved in policy making organizations are depended on review of literature to review and synthesize evidence based information.
It helps to;
-gain knowledge on a topic
-gather evidence to critique of existing nursing practice or recommend or implement the new nursing interventions
-develop proposals
-develop a theory or conceptual framework
-revise curriculum of nursing
-develop policy statements and practice guidelines

Sources of literature reviews 

• Electronic literature reviews

Most of the universities offer electronic data base with bibliographic files that can be accessed either through an online research. Nurses can access the data through online search, CD-ROM (Compact disks that store the bibliographic information) or commercial vendors (Ovid, Silver platter and so on). These services provide trial run for a few months for testing accessibility before subscribing. For example, CINAHL (Cumulative index to nursing and allied health literature), MEDLINE (Medical literature online), AIDSLINE (AIDS information online), CANCERLIT (Cancer literature) and CHID (Combined health information data base). In the electronic research data base, the studies can be searched by the key words, variables and researcher’s name.

• Print resources

These sources are overshadowed by electronic resources. The main disadvantages are time consuming due to manual search and unable to access to all researchers widely. The main advantage is one can access to reports before 1982, as it is not published in electronic sources.
Print indexes are books used to locate research reports in journals and published periodically with an annual cumulative index. For example, International nursing index, Index Medicus and so on. When using a print index, you need to first identify the appropriate subject heading. It can be located in Index’s thesaurus, which lists commonly used terms or key words. Abstract journals are useful for researchers, as they provide a summary if a study rather than lengthy report.

Writing a literature review
Researcher can collect reviews from two sources such as primary and secondary sources. The primary sources are written by the researchers who conducted them. The secondary sources are description of research articles prepared by some one. The review articles help the researcher to gin insight on what is known and what is unknown or related topic. 

The steps of preparing a written research review are:
Step 1: Identify the key words/concepts to be searched
Step 2: Identify the potential references through electronic/manual search
Step 3: Retrieve promising references
Step 4: Screen references for relevance and appropriateness
Step 5: Read relevant articles and concise the reports
Step 6: Organize the reports based on subject/year/nature of the results
Step 7: Write a review

Types of literature references
There are varieties of literature such as empirical literature, conceptual literature and others include opinion articles, anecdotes, incident reports or clinical impressions.
Empirical literature is objective and addresses the research questions with evidence based information. It increases the strength of the study.
Conceptual literature is based on a theory or conceptual model. In the conceptual literature, a primary source is a description of theory, written by the developer of the theory and a secondary source is a discussion or critique of the theory. Opinion article, anecdotes, incident reports and clinical impressions are mostly subjective; an expression of point of view by the researcher and it does not address any research questions. However, it plays an important role in formulating research ideas. 

Organizing the review
After collecting the relevant articles, the researcher should read carefully till she understands the research. The researcher prepares a summary of article by highlighting the main points such as author, year of the study, place of the study, type of approach and design, sample, data collection, data analysis, results, interpretation, implications, inconsistencies in the results, faults in the research and weakness of the research.

Types of literature reviews
There are several types of review that can be used to support evidence based practice such as:
1. Traditional narrative reviews
This type of review synthesizes and summarizes, in narrative terms, a body of research literature. These reviews are frequently published in nursing journals. It provides the state of the art research based information and foundation for the development of innovations for clinical practice.
2. Meta analysis
It is a method of integrating quantitative research findings statistically. Here, the writer will consider the individual studies are the unit of analysis in a meta-analysis. The writer will review the findings from multiple studies on the same topic are then combined to create a data set that can be analyzed. While reading meta-analysis, the reader gets an idea of strength and weakness of association of dependent and independent variable on related topic. 

3.Qualitative meta-synthesis
It is an integration of narrative information and summary of qualitative findings. It has been defined as the ‘theories, grand narratives, generalizations or interpretive translations produced from integration or comparison of findings from qualitative studies. 

To conclude, the nurses have to read literature reviews to gain insight on the various problem statements and its findings that is existed in the society, which helps to equip them to explore from known to unknown world.