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Searching the Literature and
selecting the right references
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?
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
Lit. Review: Not just a summary….
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.
….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
• Medical library resources
• Review articles
• Databases of medical literature
Medline
Full-text databases
Electronic journals
Searching with PubMed
http://www..pubmed.gov
Developed by the National Center for Biotechnology
Information (NCBI) at the National Library of Medicine,
located at National Institute of Health
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.
*
Keywords
• 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
Search strategies
“Mass Drug
Administration”
“Lymphatic
Filariasis”
66
786
“Filariasis” AND “Mass Drug Administration”
28
Search strategies
“Mass Drug
Administration”
“Lymphatic
Filariasis”
66
786
“Lymphatic Filariasis” OR “Mass Drug Administration”
824
Search strategies
“Lymphatic
Filariasis”
“Mass Drug
Administration”
758
“Filariasis” NOT “Mass Drug Administration”
Limits
• Publication type
• Ages
• Language
• Publication date
• Humans or animals
• Gender
• Entrez dates
Obtaining articles
• Full-text articles
• Medical library
• Full-text databases
*
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
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
• Outline
– Introduction
– Empirical literature
– Summary
Introduction
• Indicates focus or purpose of review
• Describes organization of review
• Indicates basis for ordering
– Most important to least
– Earliest to most recent
Empirical 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.
Summary
• Concise presentation of the research
knowledge about a selected topic—what is
known and not known
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
Hawaii,
risk factors of leptospirosis USA
in Hawaii
Bovet P etal
1999
Risk factors associated
with clinical leptospirosis--
Seychelles
Sarkar U etal
2002
Population based casecontrol 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