Search Strategy

Margaret Vugrin, MSLSDeborah West, MLS

Travis Real, MLISJun 16, 2013

Goals & Objectives

•Improve students’ ability to construct strong search strategies in PubMed:

• Basic terminology is explained

• Appropriate usage examples is presented

• Questions are supplied for practice

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Introduction• The old saying “Garbage in, garbage out”

holds true for developing strong searching skills.

• If you “Ask” the right question, you will “Acquire” the information you are seeking.

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Database Used — PubMed• Examples are based on the PubMed database

PubMed is: Free Available to anyone at anytime on the Internet Over 20 million records from over 7,000 publications Updated daily Covers fields of:

medicine, nursing, dentistry, veterinary medicine, health care system, pharmacology, and allied health

International in scope

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Boolean Operators—Glossary Boolean Operators — logic system used to combine search terms

AND OR NOT

• Controlled Vocabulary_ These are terms that are specifically indexed by human catalogers, or automated computer indexers, that link specific search terms with intended search results or articles). The controlled vocabulary we will cover in this module is MesH(Medical Subject Headings) from the National Library of Medicine Pubmed database.

• Nesting_ This is a search strategy in which the user informs the computer to search a specific way by use of parenthesis. A computer will usually read a search strategy from left to right, and take precedence in searching enclosed terms before anything else.

AND: retrieves only the middle section (intersection)

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AND

OR

OR: retrieves all (left and right side)

NOT: excludes, only pink section is retrieved. Should use sparingly.

NOT

Less is More!

If you focus–in on your topic,

Even though you have fewer numbers,

Your results will be more relevant!

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Keywords

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•Stroke (Keyword) •retrieves 167,000+ records

• Keyword searching locates the term anywhere in the electronic record, even when the article’s focus is on another topic. • “Swimming strokes” will also appear in the results of this search on “stroke.”

Keyword searching does locate very recent articles that have not yet been indexed or tagged with Subject headings.

Medical Subject Headings (MeSH)

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•Stroke (MeSH) •retrieves 62,000 + records

•MeSH is the controlled vocabulary or thesaurus used in PubMed to organize articles.•Use MeSH headings to locate articles that are indexed or categorized for a specific concept. •Related words or synonyms are included.•Subject headings are easily modifed using subheadings.

“Add to search builder” to retrieve all articles indexed with this subject heading or concept.“Add to search builder” to retrieve all articles indexed with this subject heading or concept.

Major Headings

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• Stroke (Majr) •Retrieves 45,000+ records

• Limiting the subject heading to “Major Topic” locates only those articles where the focus of the article is on this main concept.

• NOTE: Fewer articles are located than when searching with MeSH; however, these articles are focused and more relevant to your search.

Check this box or select “Major Topic” when limiting articles to “Major Topic” ONLY.Check this box or select “Major Topic” when limiting articles to “Major Topic” ONLY.

Example of MeSH Relationship• MeSH is organized into thematic hierarchical categories.

• Themes are broken down into more specific concepts…

i.e. subject headings.

• Articles are indexed (tagged) for the most specific concept.

• “+” signifies that there are more specific terms available

e.g. Face +

• MeSH is updated annually.

• Most articles are tagged with 10–15 subject headings.

A Anatomy A1 Body Regions A2 Musculoskeletal System A3 Digestive System A4 Respiratory System A5 Urogenital System A6 Endocrine System A7 Cardiovascular System A8 Nervous System A9 Sense Organs A10 Tissues A11 Cells A12 Fluids and Secretions A13 Animal Structures A14 Stomatognathic System A15 Hemic and Immune Systems A16 Embryonic Structures A17 Integumentary System

A Anatomy A1 Body Regions A2 Musculoskeletal System A3 Digestive System A4 Respiratory System A5 Urogenital System A6 Endocrine System A7 Cardiovascular System A8 Nervous System A9 Sense Organs A10 Tissues A11 Cells A12 Fluids and Secretions A13 Animal Structures A14 Stomatognathic System A15 Hemic and Immune Systems A16 Embryonic Structures A17 Integumentary System

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“Do not include indented MeSH terms”

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• All subject headings indented and below the chosen subject heading “Stroke” will automatically be included in the search strategy unless the “Do not include…” option is selected.

• This broadens the search as related subject headings are added automatically.

i.e., Brain Infarction etc. is not included in this search

Do not include MeSH terms found below this term in the Mesh Hierarchy.

MeSH Subheadings

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• Stroke (MeSH) with subheading: “therapy”

•Retrieves 25,000+ records

• Stroke (Majr) with

subheading: “therapy”•Retrieves 16,500 + records

Subheadings NARROW the subject heading.e.g., diagnosis of stroke or genetics of stroke or therapy of stroke

Select as many descriptors as you need. Select as many descriptors as you need.

AbnormalitiesAdministration & dosageAdverse effectsAgonistsAnalogs & derivativesAnalysisAnatomy & histologyAntagonists & inhibitors

BiosynthesisBloodBlood supply

Cerebrospinal fluidChemical synthesisChemically inducedChemistryClassificationComplicationsCongenitalContraindicationsCytology

HistoryImmunologyInjuriesInnervationInstrumentationIsolation

Legislation

ManpowerMetabolismMethodsMicrobiologyMortality

Nursing

SecondarySecretionStandardsStatistics & numerical dataSupply & distributionSurgery

Therapeutic useTherapyToxicityTransmissionTransplantation

UltrasonographyUltrastructureUrineUtilization

VeterinaryVirology

MeSH Subheadings

• Subheadings NARROW the subject heading. • Usually they are combined with the subject heading

• e.g., stroke/therapy (where “stroke” is the subject heading

& “therapy” the subheading)

Organization

ParasitologyPathegenicityPathologyPharmacokineticsPharmacologyPhysiologyPhysiopathologyPoisoningPrevention & controlPsychology

Radition effectsRadiographyRadionuclide imagingRadiotherapyRehabilitation

DeficiencyDiagnosisDiagnostic useDiet therapyDrug effectsDrug therapy

EconomicsEducationEmbryologyEpidemiologyEthicsEthnologyEtiology

GeneticsGrowth & development

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Advanced Search

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The Advanced Search page shows your search strategies and search results. These search statement numbers e.g. #4 or #6 can be combined with each other or with new search terms using Boolean logic operators “AND”. “OR”, “NOT”.

NOTE: The result numbers in your search sets will be different since the database is updated DAILY!

Limits

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Commonly used modifiers are located within the “Limits” table.

The Boolean operator “OR” is the default operator within boxes.

e.g., meta-analysis or practice guideline from the

“Types of Articles” box, retrieves articles of either publication type.

The Boolean Operator “AND” is the default operator between boxes.

e.g., English from the “Languages” box combined with “All Adult: 19+ years”

retrieve articles that are in English and deal with adults over 19 years of

age. All concepts must be present for retrieval.

See Boolean Slide

Databases:

1 AND 2 AND3

OR

Do you need… ?

subheadings

dates

limiters such as:

languagehuman or animal

age groupspublication types

journal subsets

SearchQuestion:

4AND

This form can help organize your strategyThis form can help organize your strategy

PubMed: How to Search Step–by–Step

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From the PubMed homepage Click on MeSH Database…to search by concept.

SelectSelect

Review Point• Using the major Boolean operators “And,” “Or,”

and “Not,” a search strategy can be refined to effectively locate articles on specific topics.

The Boolean operator “And” means that an article MUST be indexed for “Both” terms

(e.g., Hellp Syndrome “And” Pregnancy…both concepts will be in all the articles)

True or False?

Review Point True

When using the Boolean operator “And,” articles are indexed for both terms. Only the articles in the intersection will be retrieved.

See Boolean operators slide

PubMed: How to Search Step–by–Step

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To search by subject heading from the PubMed homepage Click on MeSH Database….

SelectSelect

Using MeSH

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Step 1) On the MeSH page: Type needed term. Then Click “Search”

PubMed: How to Search Step–by–step

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Step 2) Select subheading(s) (optional) based on your search needs. Step 3) “Add to search builder”

Step 4) Then: “Search PubMed”

Step 1) From the MeSH page: Type needed term. Click “Search”

strokestroke

X

X

PubMed: Results 1st Concept

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1) 1st subject heading results

Results after Boolean “And” slide

Using MeSH – 2nd Concept

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1) Repeat steps/selections with 2nd concept

Using MeSH – 2nd concept

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2) 2nd concept selections, “Add to search builder”

3) 2nd concept results

Results after Boolean “And” slide

Using Advanced Search with “And”

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3) Click on 1st # (#3)

4) Then select appropriate

Boolean operator.

5) Repeat with 2nd # (#5)

6) Then Click on

1) Choose

2) New screen opens up

NOTE:Numbers were entered automatically into “Search Box” as each new term was added to the “Search Builder.” (after following steps to left)

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Results after using Boolean “And”

Refer back to “Results #1 and #2 slides. Notice how the numbers have changed drastically.

Now use “Limits” to further focus your results.

#3 AND #5#3 AND #5

Limits – can be used to narrow results

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Choose appropriate options.Click on

Default within boxes is “Or”

Default between boxes is “And”

Results after using “Limit”

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There are 8 articles focused on research topic! (These numbers will change over time.)

To view further information on article(s) click on small box(es) next to number(s).

To view “Abstract” select “Display Settings” and follow directions on next slide.

Abstract Format

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• To view “Abstract” format:

•Choose “Display Settings”

• ON THE POP–UP SCREEN

• Select “Abstract” etc.

• “Apply” selections

• NOTE: icons to retrieve full-text ONLY visible in “Abstract” format

Access Information

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Email ResultsFrom the PREVIOUS list of results:

select (the little boxes) of the articles needed to print, email or order.

Then select: and choose appropriate button for needed activity.

Future Study

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From Library Home Page> Databases> PubMed then select: Tutorials.

Practice Question #1• Research current trends and utilization of health

care services in rural Texas.

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Answer: Practice Question #1

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This strategy located 5 articles on March 8, 2011

This is a possible strategy to answer Practice question #1. (Read strategy from the bottom up.)

NOTE: As the database is updated daily the “Results” numbers will change therefore the document retrieval numbers have been removed.

Locating the correct subject heading or MeSH term and then using appropriate subheadings creates a good strategy for this question.

Practice question #2• Does use of finasteride prevent the risk of

developing prostate cancer in the male population over 65yrs of age?

• Limit to Randomized Controlled Trial, English and Human

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Answer #2a: Practice Question

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This is a possible strategy to answer Practice question #2. (Read strategy from the bottom up.)

As the database is updated daily the document retrieval numbers have been removed.

This strategy located 8 articles on March 14, 2011

This is a possible strategy to answer Practice question #2 . (Read strategy from the bottom up.)

NOTE: As the database is updated daily the “Results” numbers will change therefore the document retrieval numbers have been removed.

Answer #2b: Practice Question

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This strategy located 8 articles on March 14, 2011

Here the subheadings were not selected right away but were added later to further refine the full subject heading results.

This is a possible strategy to answer Practice question #1. (Read strategy from the bottom up.)

NOTE: As the database is updated daily the “Results” numbers will change therefore the document retrieval numbers have been removed.

Practice Question #3• Can better communication among staff in the

operating room prevent medical errors?

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Answer: Practice Question #3

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This is a possible strategy to answer Practice question #3. (Read strategy from the bottom up.)

As the database is updated daily the document retrieval numbers have been removed.

This strategy located 14 articles on March 8, 2011

Sometimes locating the obvious subject heading is not easy…consider other synonyms that have similar meaning.

This is a possible strategy to answer Practice question #3. (Read strategy from the bottom up.)

NOTE: As the database is updated daily the “Results” numbers will change therefore the document retrieval numbers have been removed.

Summary…Final Points• Using database tools:

Boolean operators Subject headings (MeSH) Subheadings Major headings Limits

• Appropriately…• Increases relevancy and accuracy of results.

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