Literature Review

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Nov 8, 2013 (3 years and 8 months ago)

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Literature Review

Payam Kabiri, MD. PhD.

Epidemiologist


Department of Epidemiology & Biostatistics

School of Public Health

Tehran University of Medical Sciences


What is Literature?


What is Literature Review?


What kind of Literature do we have?


When the Literature review should be down?


When to use Literature in proposals?


How to refer to the used Literature?

Literature Review

نوتم ر
و
رم


وجتسج

و

ليلحت

دنم ماظن

عبانم

(
معا

زا

،هلاقم

،بات ک

همان ناياپ

و

...
)

هک

کيرد

هنيمز

یعوضوم

صاخ

رشتنم

هدش

تسا
.



نوتم ر
و
رم تيمها


راک هب ريز دراوم رد و دريگ یم ت
ر
وص شه
و
ژپ عوضوم ساسارب نوتم ر
و
رم
د
و
ر یم
:


یتاقيقحت
ح
رط لا
ز
وپ
و
رپ هيهت رد


همدقم

و
هلاسم نايب


هلاقم و ی ياهن شرازگ ميظنت رد


همدقم
و
ثحب


دننام دراوم رياس
...


Steps of Literature
Review


Problem formulation


which topic or field is being examined and what are its
component issues?


Literature search



finding materials relevant to the subject being explored


Data evaluation



determining which literature makes a significant
contribution to the understanding of the topic


Analysis and interpretation


discussing the findings and conclusions of pertinent
literature


اپ تاعلاطا
ي
ه
(Basic Knowledge)



بات ک

عجرم یاه
(Text book)




دم

از
و
ر تاعلاطا
(Updated Knowledge)


تلاجم

ی
راودا تايرشن و

(Periodicals)


Information Resources

Information Resources


Print Materials


Electronic Materials

www.iranmedex.com



Local Data

www.magiran.com

www.irandoc.ac.ir

www.srlst.com

www.sid.ir

www.pubmed.com


International Data

Information Resources

Print Materials


Journals & Papers


Indexes


Dissertations & Thesis


Abstracts of Seminars


Books & Booklets

Bibliographic database

A
bibliographic

or
library database

is a
collection of
bibliographic

information.


May contain information about
papers
,
books

and other materials held in a library.

Databases


General Databases

(Comprehensive OR Core Databases)



Specialized Databases

(Subjects Specified Databases)

General Databases

(Comprehensive OR Core Databases)


Medical Sciences


Medline


Embase


Scopus



All Sciences


Web of Sciences


Biological Abstracts


International Pharmaceutical Abstract


PsychInfo


CINAHL


Chemical Abstracts


Agricola


Econlite

Specialized Databases

(Subjects Specified Databases)

Citation Databases


Web of Science


Scopus


Google Scholar


Electronic Journals & Collection


Elsevier Science


Ovid


Blackwell Science


Oxford university Press


Springer


Proquest


Ebsco

Also Note Biases


Publication Bias


Fulltext Bias


Language Bias


Database Bias







Publication Bias



“Publication bias refers to the greater
likelihood that studies with positive results
will be published”



JAMA
2002
;
287
:
2825
-
2828

Publication Bias


Positive trials are more likely to be submitted
for publication


Positive trials are more likely to be published


Positive trials are more likely to be published
quickly



Stern and Simes
BMJ
1997
;
315
:
640
-
645

Publication Bias


Sterling study:
97
% of papers published in
4
psychology journals showed statistically significant
results at alpha level
5
% !


Dickersin study: compared published RCTs with
unpublished ones .results:
55
%pub,
15
% unpub,
favoring new therapy!


Mahoney stuD:
75
reviewers asked to review
different versions of a fictitious manuscript.
”introduction” & ”methods” : identical, ”results” &
“discussion” : different (+/ambiguous /
-
). results of
reviewers evaluation : manuscripts with “positive”
results received higher average scores!


Publication Bias


1
)…if they had reached sig.


2
) positive result


3
) interesting results for both reviewers &
authors!


4
) language bias (ENG) in being included in
a meta
-
analysis.



Searching Libraries for Thesis & Research
Reports


Searching Registries


Searching Grey Literature


Searching especial Journals like:



Journal of Negative results in Biomedicine


How to Bypass Publication Bias

نيلادم يتاعلاطا كناب اب ی يانش

ا

Index Medicus

National Library of Medicine
(NLM)

Dr. John Shaw Billings


John Shaw Billings


(US Army general Surgeon)




Director of the NLM


established Index Medicus
.

Index Medicus


Making:


Author Index


Subject Index



They call it:


Index Medicus

M
ed
ical
L
iterature
A
nalysis And
R
etrieval
S
ystem

نيلادم يتاعلاطا كناب اب ی يانش

ا

MEDLARS

MED
LARS ON
LINE


MEDLINE

نيلادم يتاعلاطا كناب اب ی يانش

ا

ک ين
و
رت لا ه سن نا مه ع او رد نيلاد م يتا علاطا ك ناب
و د ي س ه سن ت
ر
وص هب هک تسا ي پاچ سوكيدم سكدنيا
ر شتنم بو ا ي


دوش يم
.

نيلادم يتاعلاطا كناب اب ی يانش

ا

Medline


3200
Journal First & Now +
4900
Journal


More
250
,
000
Paper per Year


75
% of the Whole Printed English
Papers throughout the world


Over
17
,
000
,
000
Records Till Now


Medline


1966
up to now


National Library of Medicine (NLM)
Product


More than
17
,
000
,
000
Record till
now


The most used database by Medical
Researchers throughout the world

Medline


Publish more than
800
papers per day


Covers Medical, Dental & Nursing
papers


In
2006
,
4
,
928
journals are currently
indexed for MEDLINE


Available online through web since
1971
.

نيلادم يتاعلاطا كناب اب ی يانش

ا


Records


Fields


Titles (Ti)


Authors (Au)


Source (So)


Journal Name (Jn)


Main Abstract (MA)


Medical Subjects Headings (MESH)


………………………………………………


نيلادم يتاعلاطا كناب اب ی يانش

ا


Search Methods

1.
Find (Search)

2.
Index

3.
Thesaurus (MeSH)


Output Options

1.
View

2.
Download

3.
Print

4.
Email

نيلادم يتاعلاطا كناب اب ی يانش

ا


Operators

1.
AND

2.
OR

3.
NOT

4.
ADJ



Boolean Logics

Shaded areas
indicate retrieval

Search Statement

Types of records
retrieved




stress
AND

anxiety

Documents that have

either

stress
AND

anxiety




stress
OR

anxiety

Documents that have

both

stress
OR
anxiety




stress
NOT

anxiety

Documents that have

stress
but NOT

anxiety

Truncation


For singular, plural or word
-
roots findings.


Examples:


child*

will retrieve
children, childhood, childlike


adolescen*

will retrieve
adolescent, adolescence, adolescently


derm*
will retrieve

dermal, dermatitis, dermatology, dermoid,
dermatologist, dermatopathologist, …



Be very careful of small word roots when looking for plurals…


cat* rat*


catastrophe rational


cataract ratify


category



ratio



Rather use: (cat OR cats) (rat OR rats)

Some comparisons between the MEDLINE of
1971
& the MEDLINE of today

Items

1971

2006

Indexed
Journals


239

4,928

Users

25

77,000,000 unique visits &
about 800,000,000 searches

Server

an IBM 360/50
mainframe computer

on 20 Dell PowerEdge, 2
CPU 8Gb RAM, with the
Linux operating system


PubMed


PubMed

is available via the NCBI



Entrez retrieval system
. It was
developed by the
National Center for
Biotechnology Information (NCBI)

at
the
National Library of Medicine
(NLM)
, located at the
National
Institutes of Health (NIH)
.



MEDLINE Facts

Producer

National Library of Medicine, Washington, DC.

Subjects

medicine, dentistry, nursing, preclinical sciences, health care
systems, veterinary medicine

Size

4500+ journals indexed; 14 million references

Scope

Journals from 70 countries (>50% US)

Languages

30+

Abstracts

included for >75% of references; author
-
written


Coverage

1966


present

PubMed & Medline

Chart last updated: April
7
,
2008

Data

Total Records
?
Dates
Covered

Indexed Records
Added

PubMed

17
,
887
,
371

1949
-
present



Medline

16
,
488
,
995

1966
-
present


,
ㄷ1

In Process

239
,
052





OldMedline
?
451
,
105

1949
-
1965

About
1
,
800

How to refer to the used
Literature?


International Committee of Medical Journal
Editors (www.icmje.org)


Uniform Requirements for Manuscripts
Submitted to Biomedical Journals


Sample References (Vancouver)



www.nlm.nih.gov/bsd/uniform_requirements.html

http://www.pubmed.com

http://www.ncbi.nlm.nih.gov/

How to see where a journal is
indexed?


To check in which database a journal is
indexed & where we can find its full text,
search your journal name in these websites:



http://jake.openly.com/



http://journalseek.net/


دینزب
!

Email
دیتشاد لیم رگا

payam.kabiri@gmail.com