5 GRADE Search of the literature - European Commission · 2016-06-03 · Search of the literature Theodora Mouratidouand Carlos Martin Saborido ... 10:15-11:00 Types of questions

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Disc laimer: The contents of this presentation are the views of the author and do not necessarily represent an offic ial position of the European C ommission. © European Union, 2013

Search of the literature

Theodora Mouratidou and Carlos Martin Saborido

Public Health Policy Support Unit

Institute for Health and Consumer Protection

(JRC-IHCP)

2 GRADE Workshop – Ispra– 11-12 December 2013

GRADE Workshop: Agenda

9:00 - 10:15 Introduction. Guideline development process and the GRADE approach

10:15-11:00 Types of questions. Framing a question: PICO question. Exercise

11:00-11:15 Coffee

11:15-12:00 Choosing outcomes. Relative importance of outcomes. Exercise

12:00-12:45 Study designs. Exercise

12:45-13:30 Lunch

13:30-14:30 Search of the literature. Exercise

14:30-15:00 Determinants of quality of evidence: What can lower the evidence? (I)

15:00-15:15 Coffee

15:15-17:00 Determinants of quality of evidence: What can lower the evidence? (II) Exercise

9:00-11:15 Determinants of quality of evidence: What can lower the evidence? (III)Determinants of quality of evidence: What can upgrade evidence?

11:15-11:30 Coffee

11:30-13:00 Going from the evidence to the recommendation. Exercise

13:00-13:45 Lunch

13:45-16:00 Using the Guideline Development Tool (GDT) software. ExerciseFeedback and conclusions


a. Introduction

b. Search evidence in Medline

c. Search evidence beyond Medline

d. Other sources of evidence

e. Practical exercise

Outline


• Databases used will depend on a number of factors including the

research question, the study design of studies to be included as well as

on your resources!

– RCTs: Medline, Central, EMBASE

– Systematic Reviews: Medline, CDSR, EMBASE, DARE

– Health Technology Assessment: HTA database + websites

– Guidelines: Medline, NGC, GIN, websites

– Diagnostic tests: Medion

– Nursing aspects: Cinahl

Searching where?


• PubMed Central (PMC) is the National Library of Medicine's digital

archive of full-text journal literature

– > 6000 journals, 20 millions articles

– Free of charge

– 65% RCTs

– US-based, biased towards english (91%)

• http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed

Medline


– How is the the MeSH used

– Search strategy

– Managing results

– Saving search strategies

– Getting the articles

Searching MEDLINE

……….a specific set of terms used to describe each article……………

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• Balance between sensitivity (attempts to retrieve all relevant documents

by using a broad search) and specificity (attempts to retrieve only

relevant documents in a small precise search). A happy medium is

desirable!

• Boolean logic (allow you to broaden or focus your search results)

x AND (y OR z) will retrieve records that contain the term x, as well as one

or both of the terms y OR z

Search strategy

AND OR NOT


• Articles are indexed using a powerful vocabulary called MeSH

• The MeSH Database provides the option of identifying appropriate MeSH

terms for searches

• Represent concepts found in the biomedical literature arranged in a

hierarchical manner called the MeSH Tree Structure (16 main branches)

• > 25000 MeSH descriptors

• > 172000 ‘entry terms’

• MeSH terms are "exploded" automatically to retrieve citations that carry

the specified MeSH (sub) heading and also retrieve citations that carry

any of the more specific MeSH (sub) headings indented beneath it in the

Tree structure.

Medical Subject Headings (MeSH)

9 GRADE Workshop – Ispra– 11-12 December 2013 10 GRADE Workshop – Ispra– 11-12 December 2013


• Medline indexers assign the most specific MeSH heading(s) appropriate

to describe the main concepts discussed (or the closest one)

• Generally 5 to 15 MeSH

• MeSH terms reflecting the major points of the article are marked with an

asterisk (*)

• Information the indexer provides includes:

� topic of article

� age group of population studied

� human vs. animal studies

� type of article (e.g., review article)

MeSH


• The MeSH Database allows you to:

� Locate and select MeSH terms, (Headings, Subheadings, &

Publication Types); Supplementary Concept terms (Substance

Names) and Pharmacological Action terms

� See the definition and other helpful information for a MeSH term

� Build a PubMed search strategy

� Display MeSH terms in the hierarchy

� Limit MeSH terms to a major concept for a search

� Attach subheadings for a search

� Link to the NLM MeSH Section's MeSH Browser

• Not all databases allow MeSH searches! And searching with MeSHheadings will exclude in process and publisher-supplied citations, as theyare not indexed with MeSH

MeSH database

http://www.nlm.nih.gov/bsd/disted/pubmedtutorial/020_490.html

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• PubMed automatically searches for phrases during Automatic TermMapping (ATM)-process to find a match to unqualified terms that areentered into the query box

• If you want to force a phrase search, you can do so by:

• Enclosing the phrase in double quotes:"fecal transplant"

Note: The absence of a search tag indicates the search should be conductedin All Fields

• Entering the phrase with a search tag:robotic surgery[tw]

• Hyphenating:first-line

• Truncating:citizen jur*

Phrase Searching



• Using quotes, search tags, hyphenation or truncation instructs PubMed to

bypass ATM. Instead PubMed looks for the phrase in its Index of

searchable terms. If the phrase is in the Index, PubMed will retrieve

citations that contain the phrase

• PubMed may fail to find a phrase because it is not in the Index

• Your phrase may actually appear in citation and abstract data, but may

not be in the Index. If this is the case, the double quotes are ignored and

the phrase is processed using Automatic Term Mapping



• Truncation: search method in which symbols are used in place of letters

or words to broaden search

- Asterisk (*)

e.g. Medic*: “medical” or “medicine”

- Question mark (?)

e.g. Analys?s: retrieve “Analysis” y “Analyses”

e.g. Meta?analysis: retrieve “metaanalysis” AND “ meta-

analysis”

• Truncation turns off mapping on both unqualified or qualified terms.

Truncation terms (*,?)


• Is available on the Advanced Search page showing your searchstrategies and number of items found for each search

• Can hold a maximum of 100 search statements

– The History screen displays:

• Your search query

• Most recent 5 searches are displayed

• The time of the search

• The number of citations in your search results

• Search statement numbers menu for combining searches

– The search history is deleted after 8 hours of inactivity

– If a search is repeated, its original number is moved to the top

PubMed Search History



• My NCBI (personal account ; password required)

– Searches: save search strategies to get updates,including automatic e-mail updates

– Collections: save search results

– My Bibliography: collect citations for your publications

Managing results


• Links to full text resources from PubMed are available through a service

called LinkOut

Getting the articles

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• Europe-based

• > 24 million references

• +/- 7500 journals (>2000 non-Medline)

• Pharmacological journals!

• http://www.info.embase.com/

• EMTREE contains all MeSH terms as used in Medline (many as

synonyms)

– > 56000 ‘controlled descriptors’ (preferred terms)

– > 230000 synonyms (i.e. guides to preferred terms)

EMBASE


• Cochrane Database of Systematic Reviews, CDSR

• Database of Abstracts of Reviews of Effects, DARE

• Cochrane Central Register of Controlled Trials

=CENTRAL

• Cochrane Methodology Register, CMR

• Health Technology Assessment Database

• NHS Economic Evaluation Database

• http://www.thecochranelibrary.com/view/0/index.html

Cochrane Library


• Centre for Reviews and Dissemination, University of

York:http://www.crd.york.ac.uk/crdweb/

• PEDro: http://www.pedro.org.au/

• Cinahl: http://www.ebscohost.com/cinahl/

• Medion: http://www.mediondatabase.nl/

• PsycInfo: http://www.apa.org/pubs/databases/psycinfo/index.aspx

• National Guideline Clearinghouse: www.guidelines.gov

• Guidelines International Network: www.g-i-n.net

• SUMSearch: http://sumsearch.uthscsa.edu/

• TRIP Database: http://www.tripdatabase.com/

• Citation Indexes (e.g. ISI Web of Knowledge)

Other databases


• Public Health Interventions Cost Effectiveness Database (PHICED):

http://www.yhpho.org.uk/nphl/nphlresults.asp

• Database of Promoting Health Effectiveness Reviews (DoPHER):

http://eppi.ioe.ac.uk/webdatabases/Intro.aspx?ID=2

• Canadian Institutes of Health Research (CIHR): http://health-

evidence.ca/articles/search

• Public Health + (National Collaborating Centre for Methods and Tools,

NCCMT): http://www.nccmt.ca/tools/public_health_plus-eng.html

• And others………

Specific public health sources


• http://www.nlm.nih.gov/bsd/disted/pubmedtutorial/020_490.html



Links

Any questions?

Next:Exercise

JRC xxxxx – © European Union, 2013Disc laimer: The contents of this presentation are the views of the author and do not necessarily represent an offic ial position of the European C ommission.

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Take home example


27 GRADE Workshop – Ispra– 11-12 December 2013 28 GRADE Workshop – Ispra– 11-12 December 2013


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5 GRADE Search of the literature - European Commission · 2016-06-03 · Search of the literature Theodora Mouratidouand Carlos Martin Saborido ... 10:15-11:00 Types of questions