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

مرور متون

من�ابع نظام من�د تحلي�ل و جس�تجو پايان نام�ه کت�اب، مقال�ه، از )اعم زمين�ه موض�وعی دري�ک ک�ه )... و

خاص منتشر شده است.

اهميت مرور متون

مرور متون براساس موضوع پژوهش صورت می گيرد و در موارد زير به کار می رود:

در تهيه پروپوزال طرح تحقيقاتی

بيان مساله و مقدمه در تنظيم گزارش نهايی و مقاله

بحثو مقدمه ... ساير موارد مانند

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

ه ياطالعات پا(Basic Knowledge) (Text book)های مرجع کتاب

اطالعات روزآمد(Updated Knowledge) (Periodicals )و نشريات ادواریمجالت

Information Resources

Information Resources

Print MaterialsElectronic Materials

• Local Data www.iranmedex.com

www.magiran.com

www.irandoc.ac.ir

www.srlst.ir

www.sid.ir

•International Data www.pubmed.com

Information Resources

Print Materials

Journals & Papers Indexes Dissertations & ThesisAbstracts of SeminarsBooks & 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.

Versions of electronic databases

Index Medicus is the print version of MEDLINE Excerpta Medica is the print version of EMBASE Science Citation Index is the print version of Web of Science

Database Printed version

Electronic version

MEDLINE Since 1879 Since 1966

EMBASE Since 1948 Since 1974

Science Citation Index Since 1974 Since 1974

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

آشنايی با بانك اطالعاتي مدالين

Index MedicusNational 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

Medical Literature Analysis And Retrieval

System

آشنايی با بانك اطالعاتي مدالين

MEDLARS

MEDLARS ONLINE

MEDLINE

آشنايی با بانك اطالعاتي مدالين

بانك اطالعاتي مدالين در واقع همان نسخه الکترونيک ايندكس

مديكوس چاپي است که به صورت نسخه سي دي و يا وب

منتشر مي شود.

آشنايی با بانك اطالعاتي مدالين

Medline

3200 Journal First & Now +4900 Journal

More 250,000 Paper per Year75% of the Whole Printed English

Papers throughout the worldOver 17,000,000 Records Till Now

Medline

1966 up to now National Library of Medicine (NLM)

ProductMore than 14,000,000 Record till

nowThe 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.

آشنايی با بانك اطالعاتي مدالين

Records Fields

Titles (Ti) Authors (Au) Source (So) Journal Name (Jn) Main Abstract (MA) Medical Subjects Headings (MESH) ………………………………………………

آشنايی با بانك اطالعاتي مدالين

Search Methods1. Find (Search)

2. Index

3. Thesaurus (MeSH)

Output Options1. View

2. Download

3. Print

4. Email

آشنايی با بانك اطالعاتي مدالين

Operators1. AND

2. OR

3. NOT

4. ADJ

Boolean Logics

Shaded areas indicate retrieval

Search StatementTypes of records

retrieved

               stress AND anxietyDocuments that have

either stress AND anxiety

               stress OR anxietyDocuments that have

both stress OR anxiety

               stress NOT anxietyDocuments 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 2577,000,000 unique visits &

about 800,000,000 searches

Serveran 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

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

http://www.tums.ac.ir/http://diglib.tums.ac.ir/

http://scholar.google.com

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/

اگر میل داشتید Email ! بزنید

payam.kabiri@gmail.com

The Oxford Dictionary's latest definition of the following words

Boss: Someone who is early when you are late and late when you are early.

Cigarette: A pinch of tobacco rolled in paper with fire at one end and a fool on the other.

Classic: A book which people praise, but do not read.

Committee: Individuals who can do nothing individually and sit to decide that nothing can be done together.

The Oxford Dictionary's latest definition of the following words

Compromise: The art of dividing a cake in such a way that everybody believes he got the biggest piece.

Conference Room: A place where everybody talks, nobody listens and everybody disagrees later on.

Criminal: A guy no different from the rest....except that he got caught.

Dictionary: A place where success comes before work.

The Oxford Dictionary's latest definition of the following words

Doctor: A person who kills your ills by pills, and kills you with his bills.

Etc .: A sign to make others believe that you know more than you actually do.

Experience: The name men give to their mistakes.

Father: A banker provided by nature.

The Oxford Dictionary's latest definition of the following words

Office: A place where you can relax after your strenuous home life.

Opportunist: A person who starts taking bath if he accidentally falls into a river.

Optimist: A person who while falling from Eiffel tower says in midway "See I am not injured yet."

The Oxford Dictionary's latest definition of the following words

Lecture: An art of transferring information from the notes of the lecturer to the notes of the students without passing through the minds of either.

Smile: A curve that can set a lot of things straight.

Philosopher: A fool who torments himself during life, to be spoken of when dead.

اگر میل داشتید Email ! بزنید

payam.kabiri@gmail.com