Transcript Introduction to Database Searching

EFFECTIVE BIOMEDICAL LITERATURE
SEARCHING
NOVEMBER 7, 2014
Marcia Epelbaum, M.A.
Knowledge Management and Eskind Biomedical Library
Objectives
1.
2.
3.
4.
5.
6.
Formulate your question
Using of Boolean Logic
Building your search strategy
Controlled vocabulary
Anatomy of a PubMed Record
Resource Focus:

PubMed and My NCBI
Asking the Question: PICO
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Patient, Population or Problem
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Intervention or exposure

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What do you want to do with this patient (e.g. treat, diagnose,
observe)?
Comparison
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
What are the characteristics of the patient or population?
What is the condition or disease you are interested in?
What is the alternative to the intervention (e.g. placebo, different
drug, surgery)?
Outcome

What are the relevant outcomes (e.g. morbidity, death,
complications)?
http://healthlinks.washington.edu/ebp/pico.html
Clinical Vignette

A 54-year-old man presents for a health maintenance visit. He
has no significant medical history, has never smoked, and takes
no medications. Other than a body mass index of 26 kg per
m2, his examination is unremarkable. He has no family history
of cardiovascular disease (CVD). A recent lipid panel revealed
a total cholesterol level of 256 mg per dL (6.63 mmol per L), a
high-density lipoprotein level of 51 mg per dL (1.32 mmol per
L), and a low-density lipoprotein level of 162 mg per dL (4.20
mmol per L). You consider starting him on a statin to lower his
cholesterol level and wonder if it is likely to reduce his risk of a
cardiovascular event.
Source:
http://www.aafp.org/afp/2011/1001/p767.html
Clinical Question

Do statins reduce cardiovascular events in persons
with elevated cholesterol levels and without known
coronary artery disease?
Parsing the Question
Patients: Adult patients with no previous
CVD
Problem: Elevated cholesterol
I: Statins
C: None
O: Reduction of possible cardiovascular
events
Boolean Logic
In the context of database searching, Boolean logic
refers to the logical relationships among search terms.


The Boolean operators AND, OR, NOT can be used to
combine search terms in PubMed.
In PubMed and other databases, Boolean operators
must be entered in uppercase letters.
Source:
http://www.nlm.nih.gov/bsd/disted/pubmedtutorial/020_350.html
AND
BOTH terms included in any results.
Cardiovascular
Diseases
Statins
AND
If a record has only one of the two
terms, it will not be retrieved.
If the record has neither term, it will
not be retrieved.
What does this do to the amount of
records retrieved?
OR
‘OR’ will retrieve articles if either
concept is included.
Statins
Anticholesteremic
Agents
OR
What does OR do to the amount
of records retrieved?
NOT
Excludes any results containing the
term
statins
aspirin
Records containing both will not be
retrieved.
NOT
What does NOT do to the amount
of records retrieved?
Using OR
“OR” groupings contain terms for the same
idea/concept and are usually put in parenthesis
(term OR term OR term)
where all terms are difference ways of representing the
same concept
(“statins” OR “crestor” OR “zocor”OR “lipitor”)
Using AND
“AND” groupings contain terms for different
ideas/concepts and can combine OR groupings
Term AND (Term OR Term) where each represents a
different concept
(“cardiovascular diseases”[tiab] OR “cardiovascular
events”[tiab] OR “cardiovascular event”[tiab] OR
“CVD events”[tiab]) AND (“statins”[tiab] OR
“crestor”[tiab] OR “lipitor”[tiab]) AND (“primary
prevention”[tiab] OR prevention[tiab])
Controlled Vocabulary


A controlled vocabulary is an established list of standardized
terminology for use in indexing and retrieval of information.
It ensures that a subject will be described using the same preferred
term each time it is indexed and this will make it easier to find all
information about a specific topic during the search process.*
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Examples:
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Medical Subject Headings (MeSH)
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CINAHL Headings

PsycINFO
*http://stats.oecd.org/glossary/detail.asp?ID=6260
Search Strategy with Controlled
Vocabulary

(“Cardiovascular diseases”[Mesh] OR
“cardiovascular diseases”[tiab] OR “cardiovascular
events”[tiab] OR “cardiovascular event”[tiab] OR
“CVD events”[tiab]) AND (“statins”[tiab] OR
“crestor”[tia] OR "Hydroxymethylglutaryl-CoA
Reductase Inhibitors"[Mesh]) AND ("Primary
Prevention"[Mesh] OR “primary prevention”[tiab])
Anatomy of a PubMed Record
Title field
Abstract field
Subject Field
Publication
Types field
Putting Strategy Together
1.
2.
3.
4.
5.
Identify the concepts (Parse the question)
List specific terms for each concept
Put the terms for each concept in an OR
statements within parentheses
Combine OR statements with AND
Add any NOT statements to the end