Systematic searching in Embase using PICO to identify relevant results

1. Systematic
searching in
Embase: Using
PICO to identify
relevant results
Dr. Ivan Krstić
Product Development Manager Embase
18. XI 2015

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In this webinar, we will discuss
- Concepts that form the basis of a PICO search strategy
- How to use information in Emtree to build effective searches
- The best levels of evidence to include in systematic reviews
- How upcoming Embase enhancements will make searching using
PICO even easier

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Why is Evidence-Based Medicine Important?
“EBM solutions have the potential to accelerate and improve clinical decision
making and patient outcomes.”
To improve clinical efficiency/effectiveness
To apply proven practices in medicine
To standardize practices
To reduce unnecessary care/costs
"Evidence-based medicine is the thorough, explicit and cautious use of current
best evidence in making decisions about the care of individual patients."

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EBM is a Life-Long, Problem-Based Learning Process
that Involves:
1. Clearly defining a clinically relevant question
2. Finding the best evidence
3. Critically appraising the evidence
4. Integrating the answer with clinical expertise and apply
5. Evaluating the treatment
“We’re doing our best every single day to connect the very latest research to clinical
care so that our patients can benefit as much as possible…. We use practice-based
evidence to achieve the very best outcomes for our patients…”
–– Steven E. Lipshultz, M.D., pediatrician-in-chief at the Children’s Hospital of Michigan and
chair of Pediatrics for the Wayne State University School of Medicine

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EBM is on the Rise
“By the year 2020, 90% of clinical decisions will be supported by accurate,
timely, and current clinical information, and will reflect the best available
evidence”
–– Charter of the Institute of Medicine (IOM) Roundtable on Value & Science-Driven Health Care
Physicians to guide treatment decisions
Heathcare providers (insurers) to guide reimbursement policies
Governments to set guidelines and policy
Who uses EBM?

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Finding the Best Evidence
What are Systematic Reviews?
High-level overviews of
primary research on a
particular research
question that tries to
identify, select, synthesize
and appraise all high-
quality research evidence
relevant to that question in
order to answer it.
“The systematic review provides a verdict on unsettled medical debates based on a painstaking
reassessment of all the relevant research…the impact can be enormous. Official guidelines and “best
practices” are established or changed after systematic reviews. Legal standards defining malpractice
may be set; insurers may decide which treatments to pay for and which to decline”.

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Systematic reviews sum up the best available research on a specific question. This
is done by synthesizing the results of several studies.
A systematic review uses transparent procedures (defined in advance) to find,
evaluate and synthesize the results of relevant research. This practice is also
designed to minimize bias.
Peer review is a key part of the process; qualified independent researchers control
the author's methods and results.
A systematic review must have:
• Clear inclusion/ exclusion criteria
• An explicit search strategy
• Analysis of included studies
• Meta-analysis (where possible)
What is a systematic review?

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Preparing a Systematic Review
The Cochrane Handbook outlines eight general steps for preparing a
systematic review:
1. Defining the review question(s) and developing criteria for including
studies
2. Searching for studies
3. Selecting studies and collecting data
4. Assessing risk of bias in included studies
5. Analyzing data and undertaking meta-analyses
6. Addressing reporting biases
7. Presenting results and "summary of findings" tables
8. Interpreting results and drawing conclusions

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Using the PICO Framework to Structure a Question
P = Patient
I = Intervention
C = Comparison/control
O = Outcome
PICO is a method used to structure the elements (concepts) of the review question
into a search strategy and process.
On the next few slides, we’ll look at PICO to answer:
What are the best empirical antibiotic treatment options for bacterial meningitis?

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P (Patient, Problem or Population)
A generic formula for this search strategy is:
1. Disease Emtree preferred term
‘name of the disease’/de
2. Disease term as free text search (Titles and Abstracts)
‘name of the disease’ OR ‘synonyms for the disease’
3. #1 OR #2
e.g.
'bacterial meningitis'/de OR
'bacterial meningitis' OR 'e. coli meningitis' OR 'escherichia coli meningitis' OR
'meningitis purulenta' OR 'purulent meningitis' OR 'pyogenic meningitis'

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I (Intervention)
A generic formula for this search strategy is:
1. Drug Emtree preferred term
‘name of the drug’/de
2. Drug term as free text search
‘name of the drug’ OR ‘synonyms for the drug’
3. Include the Drug trade name (:tn) field, when appropriate
3. Drug CAS registry number Field search
‘CAS number’:rn
4. #1 OR #2 OR #3
e.g.
'antibiotic agent'/exp OR antibiotic*

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C (Comparison or Control)
The aspects of this concept may include absence of risk or treatment,
placebo or alternative therapy. This component may not apply to all
review questions.
It does not apply in our example:
“What are the best empirical antibiotic treatment options for bacterial
meningitis?”

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O (Outcome)
The aspects of this concept may include risk, mortality, morbidity,
quality of life and utilities.
Sometimes this component is not searchable and/or it is advisable to
ignore it in the search process.

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Logical Operators
Use the Boolean OR operator to search the relationship within each
individual concept.
The formula for using AND Boolean logical operators to search the
relationship between the concepts is:
P-elements
AND
I-elements
AND
C-elements
AND
O-elements

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Poll – When you build systematic reviews do you:
• Create long multi-line queries
• Create short one-line queries and combine
• I don't do Systematic Reviews

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Conduct a Scoping Search (to start)
Used to give an overview of previous work and to identify a Cochrane
review or systematic review in particular
– Can be conducted quite quickly
– Can be based on a simple search strategy
Limit topic search to Cochrane Review and/or Systematic Review
Note – Available on the Advanced, Drug and Disease search forms

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Using Previous Work
If a Cochrane review or
systematic review is found, look
for a search strategy published
in the review.
When a search strategy is
provided:
– Assess its relevance for
adaptation
– Translate search syntax,
when necessary
– Consider indexed terms
(subject headings) and free-
text terms used
– Convert subject terms, where
needed

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Hints and Tips for Searching
Always start with Emtree to identify a preferred term (subject
heading) for searching, when available

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Reviewing an Emtree Record
Take note of any Synonyms
listed
Read the entry provided from
Dorland’s dictionary
e.g. Population:
'bacterial meningitis'/de OR 'bacterial
meningitis' OR 'e. coli meningitis' OR
'escherichia coli meningitis' OR 'meningitis
purulenta' OR 'purulent meningitis' OR
'pyogenic meningitis'

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Hints and Tips for Searching
When performing an abstract and title search for any synonyms listed
in an Emtree record, consider using truncation or wildcard characters
(*, ?) as needed (e.g. antibiotic*)
When conducting a search of Article title and Abstract for author free-
text expressions consider using proximity operators (NEXT, NEAR)
as appropriate (e.g. meningitis NEAR/2 purulent*)
When performing free-text searches, remember to consider variant
spellings including British and American spellings and terminology
– e.g., tumor vs tumour; diaper vs nappy; pediatric vs paediatric;
otorhinolaryngology vs ear, nose and throat; overuse injury vs repetitive
strain injury

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Limits
The most common type of search filter is for specific study designs
Other limits applied may include language, human or animal studies,
sex and age, publication type, year(s) of publication
When using date limits, remember also to add search strings for articles in press
and records in process
• Some articles in press do not have publication dates and will be lost if not search
for specifically!

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Study Type Filters / Hedges
Common study design filters for systematic reviews include:
– RCTs
(randomised controlled trials or randomised clinical trials)
– Cohort studies
– Case-control studies
– Cross-sectional studies
Particular types of review questions are usually addressed by different
study designs.
For example,
http://hiru.mcmaster.ca/hiru/HIRU_Hedges_EMBASE_Strategies.aspx
suggests a therapy hedge that maximizes sensitivity:
random* OR (clinical NEXT/1 trial*) OR ‘health care quality’/exp
22

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Review Questions and Study Designs
Type of Question Study Type
Etiology Cohort, Case-control
Therapy RCT
Prognosis Cohort
Harm Cohort, Case-control
Diagnosis Cross-sectional, Case-control
Economic Cost-effectiveness analysis, Resource utilization,
etc.
Note – Questions that can be answered best by RCT may be answered by
meta-analysis and systematic reviews also
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Saving the Search
Use Save search for regular use of repeated search strategies
– e.g., study design, updating a search
– Or alternatively, set up an Email Alert
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Share (Export) Records
Processing of records for data collection to evaluate and critically
appraise the evidence
– i.e., extraction, quality assessment and analysis based on inclusion and
exclusion criteria
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Saving Records into Clipboard
Processing of records for data collection to evaluate and critically
appraise the evidence
– i.e., extraction, quality assessment and analysis based on inclusion and
exclusion criteria
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Document the Search Process
Export the session history to copy and paste it into a document for
inclusion in any review documentation
– Or alternatively, email it
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Summary of Search Processed
Remember to record the date the
search was processed
– If an update is needed, then
re-run the search using date
limits as well as search strings
for articles in press and
records in process
• Some articles in press do
not have publication dates
and will be lost if not
search for specifically!
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Upcoming Embase enhancements will make
searching using PICO even easier

30. Thank you!
Any questions?
Contact:
Ivan Krstić i.krstic@elsevier.com

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With Embase Critical Information isn’t Missed —
Includes all of MEDLINE (PubMed) Plus Much More
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MEDLINE
• In-depth drug, disease, device indexing with
>2x as many index terms as MEDLINE
• Unique search features to find results based on
abstract and index terms and dozens of filters
• Ability to save, share and edit complex search
strategies with a group
• Unique coverage of over 1.75m conference
abstracts from >5,5000 conferences (added
since 2009)
• Much more coverage of non-English content
and RCTs
2,700 journals not available
on MEDLINE
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30 Million Records!