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  جستجو و تحليل نظام ‌ مند منابع ( اعم از مقاله، کتاب، پايان ‌ نامه و...) که دريک زمينه موضوعی 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 مقدمه و بيان مساله در تنظيم گزارش نهايی و مقاله مقدمه و بحث 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

 اطلاعات پايه (Basic Knowledge) کتاب ‌ های مرجع (Text book)  اطلاعات روزآمد (Updated Knowledge) مجلات و نشريات ادواری (Periodicals) Information Resources

 Print Materials  Electronic Materials

Local Data 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.bibliographic May contain information about papers, books and other materials held in a library. books

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:

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:

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 اطلاعاتي مدلاين 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

Medical Literature Analysis And Retrieval System آشنايی با بانك اطلاعاتي مدلاين MEDLARS

MEDLARS ONLINE MEDLINE آشنايی با بانك اطلاعاتي مدلاين

بانك اطلاعاتي مدلاين در واقع همان نسخه الکترونيک ايندكس مديكوس چاپي است که به صورت نسخه سي دي و يا وب منتشر مي شود. آشنايی با بانك اطلاعاتي مدلاين

Medline 33200 Journal First & Now Journal MMore 250,000 Paper per Year 775% of the Whole Printed English Papers throughout the world OOver 17,000,000 Records Till Now

 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.

آشنايی با بانك اطلاعاتي مدلاين  Records  Fields Titles (Ti) Authors (Au) Source (So) Journal Name (Jn) Main Abstract (MA) Medical Subjects Headings (MESH) ………………………………………………

آشنايی با بانك اطلاعاتي مدلاين  Search Methods 1. Find (Search) 2. Index 3. Thesaurus (MeSH)  Output Options 1. View 2. Download 3. Print 4.

آشنايی با بانك اطلاعاتي مدلاين  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 Indexed Journals 2394,928 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). Entrez retrieval systemNational Center for Biotechnology Information (NCBI)National Library of Medicine (NLM)National Institutes of Health (NIH)

MEDLINE Facts ProducerNational Library of Medicine, Washington, DC. Subjectsmedicine, dentistry, nursing, preclinical sciences, health care systems, veterinary medicine Size4500+ journals indexed; 14 million references ScopeJournals from 70 countries (>50% US) Languages30+ Abstractsincluded for >75% of references; author-written Coverage1966 – present

PubMed & Medline Chart last updated: April 7, 2008 DataTotal Records Dates Covered Indexed Records Added PubMed17,887, present Medline16,488, present14,177 In Process239,052 OldMedline451, About 1,800

How to refer to the used Literature?  International Committee of Medical Journal Editors (  Uniform Requirements for Manuscripts Submitted to Biomedical Journals  Sample References (Vancouver) 

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:

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