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Nov 8, 2013 (3 years and 11 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


اي و یش
ز
وم

ا فادها اب و دريگ یم ت
ر
وص رظن د
ر
وم عوضوم ساسارب نوتم ر
و
رم
دوش یم ماجنا یشه
و
ژپ
.
نوتم ر
و
رم یشه
و
ژپ فادها
:



یتاقيقحت
ح
رط لا
ز
وپ
و
رپ هيهت


همدقم

و
هلاسم نايب



هلاقم و ی ياهن شرازگ ميظنت


همدقم

و
ثحب



دننام دراوم رياس
...


Steps of Literature Review

1)
Problem formulation & Keyword extraction


Specify the topic or field you want to search about &
extract its main concepts as keywords

2)
Literature search


Using the keywords specified in step one, we will
search all the relevant available resources

3)
Data evaluation


Appraise the found literature & select those valid
ones

4)
Analysis & interpretation


Discuss the findings and conclusions of pertinent
literature


اپ تاعلاطا
ي
ه
(Basic Knowledge)



بات ک

اه


(
B
ooks)




دم

از
و
ر تاعلاطا
(Updated Knowledge)


تلاجم

ی
راودا تايرشن و

(Periodicals)

Information Resources

So you work in a job which:


Its
half
-
time

(half
-
life) is
6
months
, &


Its
doubling
-
time

is
20
month



You works in a
ever
-
changing

&
ever
-
growing

profession !



So you should
keep updating
!

Information Resources


Print Materials


Electronic Materials

www.iranmedex.com



Local Data

www.magiran.com

www.irandoc.ac.ir

www.srlst.com

www.medlib.ir

www.sid.ir

www.pubmed.com


International Data

Information Resources

Information Resources


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



(http://scholar.google.com)


Electronic Journals & Collection


Elsevier Science


Ovid (LWW)


Wiley InterScience (Included old
Blackwell
Science)


Springer


Oxford university Press


Thieme


Proquest


Ebsco

16

بسانم یوجتسج کي ماجنا حيحص لحارم

(1
باختنا
یاه هژاوديلک

بسانم

(2
یوجتسج
عماج یتاعلاطا یاه کناب
(
ماع
)
دننام

(
Medline
،
ISI

و
Scopus
)
یبايزاب و
اه هديکچ

ش
و
ر هب
:


یوجتسج
یتغل


یوجتسج
یعوضوم

(3
یوجتسج
دوجو ت
ر
وصرد یصصخت یتاعلاطا یاه کناب

(4
هعومجم یوجتسج
تلاجم

یبايزاب و کين
و
رت کلا
Fulltext

هدش یبايزاب تلااقم

(5
یوجتسج
بو

قيرطزا
Scholar Google

هدناميقاب دراوم یبايزاب و

(6
ليلحت

هدش یبايزاب تلااقم یباي
ز
را و

(7
تاعلاطا جارختسا

جياتن یدنب عمج و تلااقم


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 کلا هخ سن نا مه ع قاو رد نيلاد م يتا علاطا ك ناب
و د ي س هخسن 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

Database


3200
Journal First & Now +
5400
Journal


More
250
,
000
Paper per Year


75
% of the Whole Printed English
Papers throughout the world


Over
19
,
000
,
000
Records Till Now


Medline


1966
up to now


A National Library of Medicine (NLM)
Product


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
,
5
,
454
journals are currently
indexed for MEDLINE


Available online through web since
1971
.

نيلادم يتاعلاطا كناب راتخاس


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

both

stress
AND
anxiety




stress
OR

anxiety


Documents that have

either

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

+5400 journals indexed; +19 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: May
17
,
2010

Data

Total
Records

Dates
Covered

Indexed
Records Added

PubMed


,
㠲8
,
㤸9

ㄹ㐹
-
灲敳p湴



Medline

18
,
073
,
746

ㄹ㘶
-
灲敳p湴


,
㌷P

In Process

346
,
843





OldMedline
?
471
,
316

1949
-
1965



,
〱0

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/

دینزب
!

Email
دیتشاد لیم رگا

payam.kabiri@gmail.com