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Literature Review Payam Kabiri, MD. PhD. Epidemiologist Department of Epidemiology & Biostatistics School of Public Health Tehran University of Medical.

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Presentation on theme: "Literature Review Payam Kabiri, MD. PhD. Epidemiologist Department of Epidemiology & Biostatistics School of Public Health Tehran University of Medical."— Presentation transcript:

1 Literature Review Payam Kabiri, MD. PhD. Epidemiologist Department of Epidemiology & Biostatistics School of Public Health Tehran University of Medical Sciences

2 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

3 مرور متون جستجو و تحليل نظام ‌ مند منابع ( اعم از مقاله، کتاب، پايان ‌ نامه و...) که دريک زمينه موضوعی خاص منتشر شده است.

4 اهميت مرور متون مرور متون براساس موضوع مورد نظر صورت می ‌ گيرد و با اهداف آموزشی و يا پژوهشی انجام می ‌ شود. اهداف پژوهشی مرور متون :  تهيه پروپوزال طرح تحقيقاتی مقدمه و بيان مساله  تنظيم گزارش نهايی و مقاله مقدمه و بحث  ساير موارد مانند...

5 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

6 اطلاعات پايه (Basic Knowledge) کتاب ‌ ها (Books) اطلاعات روزآمد (Updated Knowledge) مجلات و نشريات ادواری (Periodicals) Information Resources

7 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 !

8 Information Resources Print Materials Electronic Materials

9 Local Data International Data Information Resources

10 Journals & Papers Indexes Dissertations & Thesis Abstracts of Seminars Books & Booklets

11 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.

12 Databases General Databases (Comprehensive OR Core Databases) Specialized Databases (Subjects Specified Databases)

13 General Databases (Comprehensive OR Core Databases) Medical Sciences  Medline  Embase  Scopus All Sciences  Web of Sciences

14 Biological Abstracts International Pharmaceutical Abstract PsychInfo CINAHL Chemical Abstracts Agricola Econlite Specialized Databases (Subjects Specified Databases)

15 Citation Databases Web of Science Scopus Google Scholar  (

16 Electronic Journals & Collection Elsevier Science Ovid (LWW) Wiley InterScience (Included old Blackwell Science) Springer Oxford university Press Thieme Proquest Ebsco 16

17 مراحل صحيح انجام يک جستجوی مناسب 1) انتخاب کليدواژه‌‌های مناسب 2) جستجوی بانک‌های اطلاعاتی جامع (عام) مانند ( Medline ، ISI و Scopus ) و بازيابی چکيده‌ها به روش:  جستجوی لغتی  جستجوی موضوعی 3) جستجوی بانک‌های اطلاعاتی تخصصی درصورت وجود 4) جستجوی مجموعه مجلات الکترونيک و بازيابی Fulltext مقالات بازيابی‌شده 5) جستجوی وب ازطريق Scholar Google و بازيابی موارد باقيمانده 6) تحليل و ارزيابی مقالات بازيابی شده 7) استخراج اطلاعات مقالات و جمع‌بندی نتايج

18 Also Note Biases Publication Bias Fulltext Bias Language Bias Database Bias …

19 Publication Bias “Publication bias refers to the greater likelihood that studies with positive results will be published” JAMA 2002;287:2825-2828

20 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

21 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!

22 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.

23 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

24 آشنايی با بانك اطلاعاتي مدلاين Index Medicus National Library of Medicine (NLM)

25 Dr. John Shaw Billings John Shaw Billings (US Army general Surgeon) Director of the NLM established Index Medicus.

26 Index Medicus Making:  Author Index  Subject Index They call it:  Index Medicus

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

28 MEDLARS ONLINE MEDLINE آشنايی با بانك اطلاعاتي مدلاين

29 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

30 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

31 Medline 1966 up to now A National Library of Medicine (NLM) Product The most used database by Medical Researchers throughout the world

32 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.

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

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

35 آشنايی با بانك اطلاعاتي مدلاين Operators 1. AND 2. OR 3. NOT 4. ADJ

36 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

37 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)


39 Some comparisons between the MEDLINE of 1971 & the MEDLINE of today Items19712006 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

40 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).

41 MEDLINE Facts ProducerNational Library of Medicine, Washington, DC. Subjectsmedicine, dentistry, nursing, preclinical sciences, health care systems, veterinary medicine Size+5400 journals indexed; +19 million references ScopeJournals from 70 countries (>50% US) Languages30+ Abstractsincluded for >75% of references; author-written Coverage1966 – present

42 PubMed & Medline Chart last updated: May17, 2010 Data Total Records Dates Covered Indexed Records Added PubMed19,824,9841949-present Medline18,073,7461966-present12,370 In Process346,843 OldMedline471,3161949-1965 16,012

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


45 بزنید ! Email اگر میل داشتید

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