REVIEW OF LITERATURE Dr Reneega Gangadhar MD Professor & Head of Pharmacology Govt. T.D Medical college Alappuzha

“ Research is to see what everybody has seen and to think what nobody else had thought.” Albert Szent-Gyorgyi.

Introduction

What Is a Literature Review? It is a critical and in depth evaluation of previous research It is a summary and synopsis of a particular area of research A good literature review expands upon the reasons behind selecting a particular research question

Introduction Scholarly Writing It is the scholarly core of the dissertation Literature Review, is where most of a dissertation's sources are cited. You must locate current research studies The Literature Review shows you know where your research fits in with others.

Introduction Scholarly Writing DO NOT editorialize – just the facts! DO connect your study to what you find in the review. DO make certain that every review relates to YOUR study -- and show us HOW

Introduction Scholarly Writing You need to cite appropriate literature to provide a rationale for the study’s – research design, – instruments, and methods of data collection, – analysis, and conclusions

8 Why a literature review? The literature review will:  provide knowledge of the problem area  clearly identify the need for the proposed study  identify gaps and strengths in previous scholarly studies

Why review literature?  Clarify your research idea and sharpen your research question  Establish a theoretical framework for your study  Find investigations similar to the one you are contemplating  Learn from similar study designs

Why review literature?  Define your variables and terms clearly  Identify useful methodologies and instruments  To identify authorities or important contributors in the field

When Review of literature ?  Should begin at the time of conceiving the study  Should go on after your results are ready  Helps you to formulate your conclusions and discussion

12 Questions to be answered: What is already known about this issue/problem?” What useful data already exists that informs your efforts. What is missing from the literature that your study will provide? Why is your approach (method) an excellent way to solve the problem?

Sources of medical literature  Primary Sources: Journal articles that report original work  Print  Electronic  Secondary Sources  Textbooks  Monographs  Review Articles  Alternative Sources  Government publications  Doctoral dissertations  Unpublished data

Textbooks and monographs  Textbooks  Useful only for getting to know a topic  One or few authors; restricted viewpoint  Information at least two years old  Monographs  Authors are usually authorities in the field  Dated information

Review articles  Information is more current  Authors are specialists in the area of study  References provided are good sources of more reading material Organized search for journal articles of original research is a must

Search for medical literature  Traditional  Index Medicus  Year books  Excerpta medica  Electronic databases  Medline  Others  World Wide Web

The traditional library  Browsing the shelves  Catalogues or index cards  Books have unique identity (ISBN)  Books are permanent written records

The World Wide Web  Two billion pages of information  Grows at an exponential rate  Lacks bibliographic control standards  No equivalent to the ISBN  No standard system, cataloguing or classification  Most documents lack even the name of the author and the date of publication.

Search Engine  Huge databases  Enable quick access to vast amounts of information  Can perform searches on any keyword or subject combination  Access is totally FREE  But the things you seek may not always be at the top of the retrieved page

Medical databases  MEDLINE ~~~~  database of NLM searchable by NLM’s pubmed and several other search engines  OMIM ~~~~  Online Mendelian Inheritance in Man; The most comprehensive database on genetic diseases.  CDC WONDER (  provides a single point of access to a variety of CDC reports, guidelines, and numeric public health data

Medline  MEDLINE (Medical Literature Analysis and Retrieval System Online) is the electronic version of the Index Medicus  Over 10 million articles published in 4300 journals in 40 different languages from 75 countries  PubMed is a search interface from the National Library of Medicine (NLM) It is free.  Other search software like Ovid

Pubmed  Coverage includes medicine, dentistry, nursing, health care literature, veterinary medicine, and the pre-clinical sciences  Covers 4,600 biomedical journals  Contains over 14 million records dating back to 1950s  PubMed includes MEDLINE records, in-process records, and out-of scope citations from publisher-supplied records

Basic PubMed Searching  State what you want to find  Identify keywords  Select synonyms and variant word forms  Combine keywords, synonyms and variant word forms  Check your spelling

Basic PubMed Searching  Enter one or more terms in query box (terms are automatically combined with “AND”)  Hit “GO”  PubMed displays results in Summary format

Learn to use……..  Boolean operators  MeSH browser  History  Limits  Tags  Citation matcher  Related PubMed Articles Link  Clipboard  Bookshelf

Boolean operators  PubMed Boolean operators : AND, OR, NOT (must be typed in upper case!)  Terms are automatically combined with AND – don’t have to type this!  AND – retrieves what 2 or more sets have in common  OR – retrieves either term or set (synonyms)  NOT – excludes term or set

MeSH  "concept-based" search methodology  Medical Subject Heading (MeSH)  Over 19,000 standardised medical terms constitute the thesaurus of MeSH  MeSH is in the form of a tree where subject headings are arranged under one another with increasing specificity  82 subheadings  Trained indexers scan published articles, interpret the findings, identify the thrust or themes of these articles, and assign MeSH terms and subheadings to each article.

Dissertation and Scholarly Research: Recipes for Success 29