Searching the Literature and selecting the right references

What Is a Literature Review?What Is a Literature Review?

• A review of the literature is a classification and evaluation of what accredited scholars and researchers have written on a topic, organized according to a guiding concept such as research objective or the problem/issue you wish to address.

Why perform literature review?Why perform literature review?

1. Saves yourself from work!

Good sense of what has been thoroughly investigated and in what areas useful new work might be done.

2. Know the subject matter better

Broader understanding of the question

3. Suggest new research topics, questions, methods

Information seeking: the ability to scan the literature efficiently using manual or computerized methods to identify a set of potentially useful articles and books

Critical appraisal: the ability to apply principles of analysis to identify those studies which are unbiased and valid.

Lit. Review: Not just a summary….

Lit. Review: Not just a summary….

….but a conceptually organized synthesis of the search

….but a conceptually organized synthesis of the search

• Organize information: and relate it to the thesis or research question you are developing

• Synthesize results: into a summary of what is and isn't known

• Identify controversy: when it appears in the literature

• Develop questions for further research

Databases and basics of literature search

Databases and basics of literature search

• Medical library resources

• Review articles

• Databases of medical literature

Medline

Full-text databases

Electronic journals

Searching with PubMedSearching with PubMed

My NCBI

[Sign In] [Register]

Entrez PubMed Nucleotide Protein Genome Structure OMIM PMC Journals Books

Search PubMed

for Go

Limits Preview/Index History Clipboard Details

Developed by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine, located at National Institute of Health

http://www..pubmed.gov

MEDLINE:

• Bibliographic database covering the fields of medicine, nursing, dentistry, veterinary medicine, the health care system, and the preclinical sciences. 

• Contains bibliographic citations and author abstracts from more than 4,800 biomedical journals published in the United States and 70 other countries.

• The database contains over 12 million citations dating back to the mid-1960s

• Coverage is worldwide, but most records are from English-language sources or have English abstracts. *

KeywordsKeywords

• Major concepts or variables of a research problem or topic used to search a database

• May be single terms or phrase• Each keyword used should be listed

in a written search plan

“Lymphatic Filariasis”

786

“Filariasis” AND “Mass Drug Administration”

28

“Mass Drug Administration”

66

Search strategiesSearch strategies

“Lymphatic Filariasis”

786

“Lymphatic Filariasis” OR “Mass Drug Administration”

824

“Mass Drug Administration”

66

Search strategiesSearch strategies

“Lymphatic Filariasis”

758

“Filariasis” NOT “Mass Drug Administration”

“Mass Drug Administration”

Search strategiesSearch strategies

Limits

• Publication type

• Ages

• Language

• Publication date

• Humans or animals

• Gender

• Entrez dates

Obtaining articlesObtaining articles

• Full-text articles

• Medical library

• Full-text databases

*

Selecting Studies for the literature review

Selecting Studies for the literature review

• Read and critique studies.

• Select those of highest quality.

• Compare the purposes, methods, results, and findings of selected studies.

• Develop a table that includes essential information from each study so that comparisons can be made.

Construct an outline for literature review

Construct an outline for literature review

Develop a table of contents for the review

• Create a concept map of the major topics and the subtopics

• Build a step-by-step, hierarchical list of the points you plan to cover

Writing a Review of the Literature

Writing a Review of the Literature

• Outline – Introduction– Empirical literature– Summary

IntroductionIntroduction

• Indicates focus or purpose of review• Describes organization of review• Indicates basis for ordering

– Most important to least– Earliest to most recent

Empirical LiteratureEmpirical Literature

• Includes quality studies relevant to topic

• For each study, purpose, sample, sample size, design, and specific findings presented, using paraphrasing rather than direct quotes

• Scholarly, but brief, critique of study’s strengths and weaknesses

Ethical Issues

• Content from studies must be presented honestly and not distorted to support a selected utilization project.

• The weaknesses of a study need to be addressed, but it is not necessary to be highly critical of a researcher’s work.

• Criticism should focus on the content, be related to your project, and be neutral and scholarly rather than negative and blaming.

• Sources should be accurately documented.

• Concise presentation of the research knowledge about a selected topic—what is known and not known

SummarySummary

Title:

Risk factors of leptospirosis in Andaman islands-a matched case-control study

Objectives:

To identify potentially modifiable risk factors associated with acute leptospirosis in Andaman islands

• Introduction• Zoonotic disease of public health

importance• About causative organism• Clinical manifestations, complications

• Public health importance• Increase in incidence over the years• Large outbreaks in SE Asian countries• Important outbreaks in India

• Animal reservoir• Rodents• Cattle• Other domestic animals• Wild animals

• Modes of transmission

• Direct

• Indirect

• Risk Factors

Authors Year Title Place, country

Sasaki DM etal 1993 Active surveillance and risk factors of leptospirosis in Hawaii

Hawaii, USA

Bovet P etal 1999 Risk factors associated with clinical leptospirosis--

Seychelles

Sarkar U etal 2002 Population based case-control study of risk factors of leptospirosis during an urban epidemic

Brazil

• Active surveillance and risk factors in Hawaii

• Objectives

• Design

• Case definition

• Selection of cases, controls, matching

• Results: use of water catchment systems

Presence of Wounds

Handling animals

• Drawbacks:

• Prevention and control

• Depend on identifying source and interrupting transmission

• Modifiable risk factors identified in earlier studies

• Control measures based on modifying these risk factors

• Summary

Thank you