Searching for Evidence 101
Author: Lee-Anne Ufholz, BSc, MLIS
Date: May 14th, 2012
Conflict of interest disclosure
• I do not hold any research grants funded by
industry or serve on any advisory
committees of a pharmaceutical company.
• I have no other relevant financial
relationships with members of the
pharmaceutical industry or medical supply
companies.
2
Searching for Evidence 101
Learning Objectives
1. Understand the fundamentals of efficient searching
2. Be aware of major search engines
3. Maximize the use of key features in PubMed
4. Create advanced searches and manage auto-alerts
5. Apply the principles and skills to your own research
3
Fundamentals of Searching
• Uses crawlers/spiders that function on an
algorithm based on: frequency and location
of keywords, how long the page has existed,
the number of other pages linked back to
that page.
• Google is a great tool for browsing the web
for answers to straightforward, factual
questions.
4
Fundamentals of Searching
Thai restaurant in my neighbourhood
5
Fundamentals of Searching
How do I get software to complete a task?
6
Fundamentals of Searching
Wikipedia is written collaboratively by largely
anonymous Internet volunteers who write
without pay. Anyone with Internet access can
write and make changes to Wikipedia
articles…
Users can contribute anonymously, under a
pseudonym, or with their real identity, if they
choose.
7
Fundamentals of Searching
What’s missing?
•Peer review of items posted to the web.
•The ability to perform a systematic,
reproducible strategy.
• Browsing is not sufficient for finding evidence
effectively.
8
Fundamentals of Searching
• The first step in creating an effective search
strategy is to clarify your question.
• Be certain that you understand what it is you need
to find.
• The current rate of research creation and
dissemination, enabled largely by the invention of
the web, makes information sharing in proportions
that were never before possible.
• The next step is to break your question into
concepts.
• PICO (Population, Intervention, Comparison,
Outcome) is a tool used often for clinical
questions.
9
Fundamentals of Searching
Question Formulation Using PICO
Population
Intervention
I
P
C
O
Outcome
Comparison
10
Fundamentals of Searching
When breaking your topic into concepts:
•As a general rule you will have 2-3 concepts in a
strategy and possibly some limits.
•It is important to consider all the possible ways a
concept can be described.
•i.e. cancer, neoplasm, oncology, carcinoma, tumour,
tumor, etc…
•perspective: disease vs. health or disease vs. pathogen
•Sophisticated databases have subject headings to
describe each concept.
•A combination of keywords and subject headings for
each concept is the most comprehensive strategy.
11
Fundamentals of Searching
Search Terms
Screen capture of search strategy worksheet
Concept 1
-AND- Concept 2 –ANDConcept 3
goes here.
OR
OR
RESIDENTS
resident(s)
residency
OR
postgraduate
education
OR
graduate
medical
education
OR
internship
SURGERY
surgery
surgical
procedures
operating
room
surgical site
DUTY HOURS
duty hours
shift worker(s)
personnel staffing
and scheduling
work schedule
work schedule
tolerance
workload
12
Fundamentals of Searching
TRUNCATION
•resident
•residents
residen*
•residency
13
Fundamentals of Searching
Questions or Comments
14
Be aware of major search engines
• Finding evidence requires consulting a
variety of resources.
• A ‘one-stop shop’ approach is not comprehensive
• Different tools provide varied levels of
evidence.
15
Be aware of major search engines
Adapted with permission from EBM Pyramid and EBM Page Generator, copyright 2006
Trustees of Dartmouth College and Yale University. All Rights Reserved.
Produced by Jan Glover, David Izzo, Karen Odato and Lei Wang.
Be aware of major search engines
Type
Resource/
Tool
Content
Use
Filtered
Cochrane Library
DARE (Database
of Review of
Effects)
4000+ systematic reviews
from the Cochrane
Collaboration, and 9000
critical appraisals of
systematic reviews from
DARE.
For locating high quality,
well-documented systematic
reviews and appraisals of
systematic reviews
Unfiltered
PubMed Clinical
Queries
Medline filters for retrieving
methodologically sound
studies. Filters created for
therapy, diagnosis,
prognosis, and etiology.
For locating systematic
reviews in the MEDLINE
database.
Synthesized
UpToDate, Dynamed
Concise, peer-reviewed and
fully references topical
summaries, focusing on
diagnosis and treatment.
For high quality peerreviewed answers to specific
clinical questions.
Mega-search
engine or
federated
search
TRIP
(Turning Research
into Practice)
Meta-search engine for 70
sources of high-quality
internet information,
including e-journals and etextbooks.
For finding pre-appraised
evidence, reviews, and
guidelines all in one place.
Be aware of major search engines
Be aware of major search engines
Be aware of major search engines
Be aware of major search engines
Be aware of major search engines
Be aware of major search engines
When choosing your tool …
• Think about your need
• What kind of question are you asking?
• Consider strengths and limits of the tool
•
•
•
•
Content frequently updated?
Content appropriate for your question?
Quick to access?
Ability to do a systematic, reproducible search?
Be aware of major search engines
Questions or Comments
Key features in PubMed
• Single Citation Matcher
• Customizing your display settings
• Related citations
• Clipboard
• Limits or filters
• Clinical Queries
• MyNCBI account
Key features in PubMed
Key features in PubMed
Key features in PubMed
Key features in PubMed
Key features in PubMed
Key features in PubMed
Key features in PubMed
Key features in PubMed
Questions or Comments
Advanced Searching and Auto-Alerts
• Free….a service provided by the National
Library of Medicine, funded by the National
Institutes of Health.
• Over 21 million citations covering Medline
and some additional titles.
• A new journal must publish for at least 2
years before PubMed will consider indexing it
in the database.
Advanced Searching and Auto-Alerts
Medical Subject Headings (MeSH)
MeSH is the NLM controlled vocabulary thesaurus used for indexing
articles for PubMed.
Advanced Searching and Auto-Alerts
Advanced Searching and Auto-Alerts
Advanced Searching and Auto-Alerts
Advanced Searching and Auto-Alerts
Advanced Searching and Auto-Alerts
Advanced Searching and Auto-Alerts
Advanced Searching and Auto-Alerts
Advanced Searching and Auto-Alerts
Questions or Comments
Apply the principles and skills to your
own research
• The first step in creating an effective search
strategy is to clarify your question.
• Be certain that you understand what it is you need
to find.
• The next step is to break your question into
concepts.
• Usually 2-3 concepts with limits or filters.
• consider all the possible ways a concept can be
described.
• A combination of keywords and subject headings
generates the most comprehensive strategy.
Fundamentals of Searching
Search Terms
Screen capture of search strategy worksheet
Concept 1
-AND- Concept 2 –ANDConcept 3
goes here.
OR
OR
RESIDENTS
resident(s)
residency
OR
postgraduate
education
OR
graduate
medical
education
OR
internship
SURGERY
surgery
surgical
procedures
operating
room
surgical site
DUTY HOURS
duty hours
shift worker(s)
personnel staffing
and scheduling
work schedule
work schedule
tolerance
workload
45
Be aware of major search engines
Type
Resource/
Tool
Content
Use
Filtered
Cochrane Library
DARE (Database
of Review of
Effects)
4000+ systematic reviews
from the Cochrane
Collaboration, and 9000
critical appraisals of
systematic reviews from
DARE.
For locating high quality,
well-documented systematic
reviews and appraisals of
systematic reviews
Unfiltered
PubMed Clinical
Queries
Medline filters for retrieving
methodologically sound
studies. Filters created for
therapy, diagnosis,
prognosis, and etiology.
For locating systematic
reviews in the MEDLINE
database.
Synthesized
UpToDate, Dynamed
Concise, peer-reviewed and
fully references topical
summaries, focusing on
diagnosis and treatment.
For high quality peerreviewed answers to specific
clinical questions.
Mega-search
engine or
federated
search
TRIP
(Turning Research
into Practice)
Meta-search engine for 70
sources of high-quality
internet information,
including e-journals and etextbooks.
For finding pre-appraised
evidence, reviews, and
guidelines all in one place.
Apply the principles and skills to your
own research
Just one reference is enough to get started.
Apply the principles and skills to your
own research
• Single Citation Matcher
• Customizing your display settings
• Related citations
• Clipboard
• Limits or filters
• Clinical Queries
• MyNCBI account
Apply the principles and skills to your
own research
Advanced Search
Auto-Alerts
Apply the principles and skills to your
own research
Watch a tutorial or find a librarian.
Apply the principles and skills to your
own research
Questions or Comments