doing literature review

Frederick Mars Untalan

Doing Literature Search

Records, Files, Data

To Know:

Value of

research

What to search

How to search

Value of research

What to search

PLACE YOUR QUESTION iN PICO or PEOM FORMAT

Baguio Gen Hosp

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National Library of Medicine The world’s largest biomedical library

NLM is the producer of:MEDLINE PubMed MedlinePlus.gov

Visit the National Library’s Home Page at:http://www.nlm.nih.gov

PUBMED

Provides free access to medical database Links to full-text articles Provides Advanced search Links to related articles and provides

discovery tools for other data that may be of interest.

PubMed’s Sponsor

Introduction to the U.S. National Library of Medicine (NLM) The National Network of Libraries of Medicine®

 NN/LM Web site: http://nnlm.gov

What’s in PubMed Most PubMed records are MEDLINE citations. Other records include those in different stages of

processing (including records provided directly from the journal publisher) but destined to be MEDLINE citations.

A relatively small number of records that are included in PubMed but not selected for MEDLINE.

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What is MEDLINE?

The world’s largest biomedical database

MEDLINE covers:MedicineDentistryVeterinary ScienceNursingOther Biological Sciences

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What is MEDLINE?

4,800 journals are indexed

Covers all aspects of biosciences and healthcare

Database of 14+ million journal citations

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What is MEDLINE?

Covers 1966 to the present

Coverage worldwide, 85% are in English

76% have abstracts

MEDLINE

MEDLINE is NLM's bibliographic database of citations and abstracts, currently > 5,600 biomedical journals

All citations in MEDLINE are assigned

MEDLINE Citations PubMed provides access to MEDLINE Scope of MEDLINE includes such diverse topics

as microbiology, delivery of health care, nutrition, pharmacology and environmental health. The categories covered in MEDLINE include everything from anatomy, organisms, diseases, psychiatry, and psychology to the physical sciences.  

contains over 17 million references dating back to 1948.

New material is added Tuesday through Saturday.

How to search

MeSH

National Library of Medicine's controlled vocabulary thesaurus.

consists of sets of terms naming descriptors in a hierarchical structure that permits searching at various levels of specificity.

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What is MeSH?

MeSH – Medical Subject HeadingsControlled vocabulary terms

○ Brain Edema, Otitis Media, Myocardial Infarction

Practice Exercises Introduction to

MeSH

1. If you search the term “phytotherapy” in PubMed, what terms are you also searching?

ANSWER

 1. If you search the term “phytotherapy” in PubMed, what terms are you also searching?

  Aromatherapy and Eclecticism

2. How far back can you search with the MeSH term, “Proteomics?”

ANSWER

2. How far back can you search with the MeSH term, “Proteomics?”  To 2003. For 2000-2002, use

Proteome.

 3. What ages are included by the term, “Child?”

ANSWER

3. What ages are included by the term, “Child?”  6 to 12 years.

 4. What is the preferred MeSH term for “chewing?” 

ANSWER

 4. What is the preferred MeSH term for “chewing?”  Mastication.

HOW TO ACCESS PUBMED

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How do I access PubMed?

Directly at: http://pubmed.gov

Or, National Library of Medicine’s homepage: http://www.nlm.nih.gov

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PubMed Screen Layout

Feature Tabs

Query Box aka Search Box

Blue Sidebar

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PubMed.gov Translates lay terms into medical subject

headingsHeart Attack into Myocardial Infarction

Links to selected free articles through publishers’ web sites

Most articles are written for health professionals

BOOLEAN

Boolean Strategies

- If you are retrieving too many records on your topic, try adding another search term with the connector AND.

Boolean Strategies

If you are retrieving too few records on your topic, try adding another search term with the connector OR.

Boolean Strategies

If you are retrieving too many records on an unrelated topic, try eliminating a word with the connector NOT.

Truncation & Wildcards To increase the number of hits retrieved, you might

consider using a truncation symbol.  Truncation will pick up variations of a word stem. Truncation symbols vary, depending on the database.

e.g., critic* will find critic, critics, criticism, critical, etc.

The wildcard symbol can be used to replace one letter in a word. This will instruct the computer to do a search and match all letters in the word and use any letter to replace the wildcard symbol.

e.g., Wom?n will retrieve records with woman and women.

Basic Searching

Quotation Marks“ “

Requires words to searched as a phrase, in the exact order you type them.

Common Words Usually Ignored + or “ ” to search them

Search which versus that.Only versus is searched on. Which and that are ignored. To require common words to be searched: +which versus +that ”which versus that”

Excluding -word -“phrase in quotes”

“acute pancreatitis” diet –cat –dog –“pancreatic cancer”

Basic Searching

OR allows more than one term

allows pages with at least one of the terms

OR requires at least one of the terms joined by it to appear somewhere in the document, in any order. “abdominal pain” OR blacks ear OR nose OR throat

The more words you enter connected by OR, the more documents you get. Broadens the search..

USES: o The OR operator is generally used to join similar, equivalent, or synonymous concepts. "global warming" OR "greenhouse effect" Abdomen Pain

Basic Searching

AND (default)

is the small overlap where both terms occur

AND is the default and only needs to be typed if you are using other Boolean operators with ( ). Ex.infopeople training is logically the same as infopeople and training

The more words you enter connected by AND, the fewer documents you get. All your words will be searched on

USES: o The AND operator is generally used to join different kinds of concepts, different aspects of the question. o "global warming" AND "sea level rise" AND california

Abdomen Pain

Basic Searching

AND NOT

excludes pages that mention PAIN, even if they also mention ABDOMINAL

Excludes documents containing whatever follows it. The AND NOT operator is generally used after you have performed a search, looked at the results, and determined that you do not want to see pages containing some word or phrase.

USES: • The AND NOT operator should be used with

extreme caution, because it eliminates the entire page, and some pages may be of value to you for other information they contain. I almost never use and not for this reason.

o "global warming" AND "sea level rise" AND NOT california - The first two terms must be somewhere and any page containing california will be thrown out.

Abdomen Pain

Basic Searching

NEAR

dogs NEAR cats

requires both terms, like AND, with the added requirement that they be within 16 words of each other

Requires the term following it to occur within a certain proximity of the preceding word in the search. In Exalead.com, NEAR requires the terms to be within 16 words of each other in either direction. Joining words by NEAR gives you fewer documents than AND, because it requires the words to be closer together.

USES: o The NEAR operator is used when you want to require that certain terms appear in the same sentence or paragraph of the document. o "global warming" NEAR "sea level rise" - Requires the two phrases to occur within 16 words of each other, in either direction.

Basic Searching

( ) parentheses:

"Nesting"

Require the terms and operations that occur inside them to be searched first. This is called "nesting."

Parentheses MUST BE USED to group terms joined by OR when there is any other Boolean operator in the search. o "global warming" AND "sea level rise" AND (california OR "pacific coast*") - Requires first two terms somewhere in all documents, and either california or pacific coast. • Parentheses also MUST BE USED with NEAR:o ("global warming" NEAR "sea level rise") AND (california OR "pacific coast*") - Requires sea level rise to be within 16 words of global warming; the rest can be anywhere in the pages. The parentheses guarantee that the effect of near stops with sea level rise.

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Searching PubMed

Let us use this search:

“I was exposed to asbestos for years in school. Can that cause gastrointestinal cancer?”

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Entering Your Search Terms Enter terms: asbestos gastrointestinal cancer

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How Does PubMed Interpret What You Type in the Box?

PubMed uses Automatic Term Mapping and maps to:

Medical Subject Headings – medical termsPhrasesAuthor Name – lastname initial(s), e.g., smith j,

smith jaJournal Titles – full journal title, MEDLINE

abbreviation, ISSN

How do you think PubMed searched your terms?

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The Details tab

The Details tab

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When to Limit?

There are many reasons for refining a search strategy. You may want to:

Exclude foreign language titlesLook for articles published within a certain

timeframeRetrieve articles that focus on women or

perhaps just children

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A quick glance at the results….

Square brackets

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The Limits tab

Limits tab

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Working with Results Citations display in batches of 20 with

most recent additions on top.

Use the check boxes to select multiple citations to view

Click on icons for more information, such as the abstract

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A Closer Look at Starting a Search

Enter search terms here and then click on Go.

Add Limits like date, language, publication type, and more.

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Related Articles

Related Articles

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Links to LinkOut

LinkOut

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The Clipboard tab Lets you keep track of the good ones while

you are still searching

How to:#1: Check the citations to keep#2: Use the Send pull-down menu to select

Clipboard#3:Click on Send.

Will keep up to 500 records for 8 hours!

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Are there other ways to limit your search?

Add additional terms to query boxcopd air pollution

Use Boolean ConnectorsAND, OR, NOT

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Combination Searching Let us use the search:

“I am looking for an article from a few years ago (maybe 4-5 years ago) by Dr. Keys

about cervical cancer treatment. It was published in the New England

Journal of Medicine.”

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Combination Searching PubMed uses Automatic Term Mapping

and maps the search terms as:

keys keys[All Fields]

cervical cancer "cervix neoplasms" [MeSH Terms]

new england journal of medicine "N Engl J Med"[Journal]

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Advanced Searching

Let us use this search:

“My neighbor had a stroke. I understand that Dr. Chin has done research on the neurological aspects

of this and it was published in the journal Neurology.”

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Preview/Index tab Preview the number of search results

before displaying the citations

Refine searches by adding one or more terms one at a time

Add terms to a strategy from specific search fields

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Preview/Index tab

To Know:

Value of

research

What to search

How to search

Frederick Mars Untalan

Doing Literature Search