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STRUCTUUR VAN EEN PUBLICATIE
1. TITEL
2. AUTEURS (naam, adres)
3. ABSTRACT (korte inhoud)
4. KEYWORDS (trefwoorden)
5. INLEIDING (context / probleemstelling)
6. METHODE EN TECHNIEKEN (o.a. statistische methodes)
7. RESULTATEN (incl. tabellen en grafieken)
8. DISCUSSIE (incl. subjectieve interpretatie)
9. CONCLUSIE
10. LITERATUUR (=bibliografie, referenties)
REFERENTIES
1. NAAM (eerste auteur)
2. TITEL
3. JOURNAL
4. JAARGANG
5. VOLUME (jaargang)
6. BLDZN (X  Y)
“Teruggaan in de tijd”
LITERATUURBRONNEN
PRIMAIRE BRONNEN
Originele full-text ARTIKELS uit TIJDSCHRIFTEN
SECUNDAIRE BRONNEN
- EXCERPTA
(korte inhouden gegroepeerd per onderwerp)
- REVIEWS
(overzichtartikels door experten over stand van zaken)
- CURRENT CONTENTS
(op weekbasis – dus actueel)
(korte inhoudstabellen van tijdschriften)
- SCIENCE CITATION INDEX (The WEB of Knowledge)
- INDEX MEDICUS (MEDLINE / PubMed in Process)
Jaarlijkse publicaties per sleutelwoorden (MeSH)
CATALOGI
adressen van bibliotheken waar tijdschriften te vinden zijn
vb. UGent-catalogus ALEPH
http://aleph.ugent.be
KLASSERINGSPRINCIPES
INDEX MEDICUS
CURRENT CONTENTS
(MEDLINE, PubMed in Process*)
SCIENCE CITATION INDEX
(The WEB of KNOWLEDGE)
PER ONDERWERP
VOLGENS TIJDSCHRIFT
VOLGENS AUTEUR
(TWEE MAANDEN)
*(DAGELIJKS)
(WEKELIJKS)
(JAARLIJKS)
CITATIES
1. 50% nooit geciteerd
2. 70% slechts 1x geciteerd per jaar
3. <1% meer dan 10x geciteerd per jaar
(minder belangrijk belangrijk)
(Garfield)
WETENSCHAPPELIJKE WAARDE - KWALITEIT
(strenge selectie!)
INDEX MEDICUS, CURRENT CONTENTS,
EXCERPTA MEDICA, ...
"Peer Reviewed, Scientific Journal cited in ..."
"Op zoek naar informatie ...”
(literatuur en kennisbanken)
- Internet
- World Wide Web en andere
- WWW-Browsers
- Medische Websites
- Robotten en andere zoekmechanismen
- Medline
ORIGINE of MEDLINE
Washington, 1864: John Shaw BILLINGS
From cataloguing “by Author” “by Subject”
 Index Catalogue of the Library of the Surgeon General’s Office
1876: National Medical Library
(1950: National Library of Medicine, NLM)
From Medical Books Medical Journals
1879: Index Medicus (bimonthly publication)
The Index Medicus will record the titles of all new publications in
Medicine, Surgery, and the collateral branches, received during
the preceeding month. These will be classed under Subject Headings,
and these will be followed by the titles of valuable original articles
upon the same subject, found, during the like period, in medical
journals and transactions of medical societies. The periodicals
thus indexed will comprise all current medical journals and
transactions of value, so far as they can by obtained (Billings 1879).
JOHN SHAW BILLINGS
- Expanding the library ( NLM)
- Cataloguing by subject ( MeSH)
- (John Hopkins Hospital & Medical School)
- Storing information on punched holes on a card
for the Census (  Hollerith cards, eleventh Census)
Tabulated Machine Company
International Business Machines (IBM)
(  IBM punch cards)
HOLLERITH CARD
John Shaw BILLINGS
Herman HOLLERITH
(1950 – 1960: Computers relying on PUNCH CARDS;
“Sorting punch cards by identifying the
intersection of two or more index terms”.
George BOOLE
Boolean searches: AND, OR, NOT
1879: INDEX MEDICUS
(printed publication)
1960: MEDical Literature Analysis and Retrieval System
MEDLARS (computerized)
1971: MEDlars-on Line
MEDLINE (on-line)
1997: PUBMED (free available, Internet / WWW)
OSTEOARTHRITIS AND IBUPROFEN
O
I
OSTEOARTHRITIS OR IBUPROFEN
O
I
OSTEOARTHRITIS NOT IBUPROFEN
O
I
Example of a search in Index Medicus
“Search on treatment of OSTEOARTHRITIS
with the drug IBUPROFEN”
MeSH
FEVER
OSTEOARTHRITIS
DRUG
INTERACTIONS
KIDNEY
FAILURE
(ACUTE)
ASPIRIN
IBUPROFEN
NAPROXEN
HEALTH
CARE COSTS
With punch cards process takes place automatically by
“SORTING”
(AND)
OPSPORINGEN DOEN in de LITERATUUR
! Taal (>90% Engels) (…Latijn)
! Synoniemen, homoniemen
! Associaties (vb. kidney, renal, …)
! Zoekstrategieën - Free Text (FIND)
- Index (MeSH) (incl. bv. synoniemen)
- Thesaurus (term combinaties)
- Lateral Searching (nieuwe ‘entries’)
- AND, OR, NOT (AND, NOT zijn beperkend)
- Limit Fields (beperkende velden)
TRUNCATION
*
WILDCARD (JOKER)
?
op het einde van een woord
om het even waar
= + niets of om het even wat
= + niets of één letter
vb. pediatri*
vb. p?ediatri*
= pediatrie
= paediatrie
= pediatrisch
= pediatrie
= pediatria
= paediatrisch
= pediatrisch
= paediatria
= pediatria
FIELDS OR INDEXES THAT ARE FREQUENTLY USED IN
MEDLINE SEARCHES (1)
(and their official Two-Letter Abbreviations)
Author (AU): initialen (bv. j, JM of xwe)
Author Address (Affilation) (AD):veranderen!
Date of Publication (DP): vb.: 1993 Nov 10 (cfr. limits)
Journal Title Abbreviation (TA)
Language (LA): meer dan 70 talen
Medical Subject Heading (MeSH) (MH): indexers gehoorzamen aan strikte
regels (specificiteit!)
subheadings; vb. SMOKING, mortality (qualifier) maakt
zoekopdrachten zeer specifiek. MeSH browser!
Text Word (Key Word) (TW): woorden uit titel en abstract; geen
stopwoorden! Not weighted, no standardised definitions
Title (TI)
INDEXEN (2)
PT : journal article, editorial, letter, controlled clinical trial,
meta-analysis, practice guideline, review
TA : Journal Title Abbreviation: Journals Database!
SB : Subset
“MEDLINE is a bibliographic, not a full-text
database, with citations to the medical
literature (usually with abstracts)”
MEDLARS (MEDical Literature Analysis and Retrieval System): 1960
MEDLINE (MEDlars on LINE): 1971
- Bibliografische database (geneeskunde, verpleegkunde,
tandheelkunde, diergeneeskunde, gezondheidszorg, ...)
- Citaties (titel, auteur, tijdschrift, abstract) uit:
- Index Medicus
- Index to Dental Literature
- International Nursing Index
-
1500-3500 nieuwe ‘citaties’ per dag (di-za)
> 33.000 nieuwe 'citaties' per maand
> 571.000 nieuwe 'citaties' toegevoegd in 2004
- PubMed in Process: dagelijks
National Library of Medicine
(NLM, Washington)
sinds 26.6.1997
MEDLINE
(>15 miljoen citaties,
gratis beschikbaar op WWW)
(>4800 biomedische tijdschriften)
PubMed
NCBI Search Engine
(> 2,2 miljoen zoekacties per dag)
MEDLINE / PubMed
http://PubMed.gov/
http://www.ncbi.nlm.nih.gov/PubMed
DOCH BETER als UGent-student via
Bib UGent  PubMed
(http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?otool=ibeuglib)
WANT SFX-knop dus meer gratis online artikelen…
(cfr. eAbonnementen UGent)
Netscape
Internet Explorer
Mozilla,…
MEDLARS
MEDLINE
PreMEDLINE
Browsers
Bibliographic Databases
Index Medicus
Printed Subject/Author Guide
PubMed
NCBI Search Engine
Web-based Retrieval Systems
(servers)
MeSH
Hierarchical Keyword System
PubMed
NCBI Search Engine
- MEDLINE en PRE-MEDLINE
- MEDLINE/PubMed, ClinicalTrials,…
- Loansome DOC delivery service
- Loansome DOC delivery service
- Medical Subject Heading (MeSH)
- Medical Subject Heading (MeSH)
- From keywords to advanced
- Search o.a. via UMLS-metathesaurus
Boolean expressions and filters (limits)
- Links to publishers full-text sites
- Search filters for diagnosis,
etiology, therapy, prognosis and
clinical prediction guides
(clinical study category); systematic
reviews; and Medical Genetics Searches
- Special Queries with links to special DBs
MeSH - WOORDENSCHAT
(Medical Subject Headings / Subheadings)
- Indexeren
- Opzoeken
... zo specifiek mogelijk ...
 23.000 search terms
Loansome - Doc
- om full text artikels elektronisch te bestellen
UMLS
Unified Medical Language System – Metathesaurus
> 1 million biomedical concepts
> 5 million concept names (from more than 100
FROM more than 100 controlled vocabularies and classifications
This Metathesaurus leads you to the most likely MeSH
for each subject entered in the query box of your interface
(e.g. in NCBI Search Engine).
Terminologie
citatie (citation)
referentie (reference)
indien publicatie R een bibliografische voetnoot bevat
waarbij verwezen wordt naar publicatie C,
dan bevat R een referentie naar C en
heeft C een citatie van R
Web-based searching with MeSH
“The most remarkable thing about MEDLINE - other than its SIZE is the amount of human energy that has gone into INDEXING
its contents.”
MEDLINE is “THE index” to the world’s medical literature and an
essential tool for assessing the SCIENTIFIC BASIS for current
knowledge about health.
Searching with AND
Ibuprofen (MeSH)
AND osteoarthritis (MeSH)
AND english (LA)
AND randomised
controlled trial (PT)
 4433 citations
 201 citations
 168 citations

77 citations
Listing in “reverse chronological order”
GRAPHIC INTERFACES: PubMed
All entries ‘automatically’ linked with Boolean ANDs
- Recommendation: PubMed
- fast
- free
- easy to use
- excellent MeSH database
SEARCH STRATEGY
(limiting)
FINAL RESULTS
(specific)
(unambigious)
AUTOMATIC TERM MAPPING
1. Een ingebrachte term wordt vergeleken met:
- de MeSH translation table
- de Journals translation table
- de Author index
2. Stopwoorden worden genegeerd
!
!
!
Knop ‘DETAILS’ aanklikken om de syntax van de Pubmed
query te visualiseren!
De functie Automatic Term Mapping wordt uitgezet als
‘truncation’ wordt gebruikt!
MEDLINE is niet sensitief voor hoofd- of kleine letters!
Web-based searching with MeSH
Term(s)
PubMed
“Automatic Term Mapping”
MeSH
Translation
Table
Journals
Translation
Table
•MeSH terms
•MeSH entry terms
•MeSH subheadings
•UMLS (synonyms)
•Names of substances
•Full title
•Abbreviation
•ISSN
Author
Index
•Last name
•Initial(s)
DETAILS: zicht op hoe ATM is gebeurd
PHRASE SEARCHING
PubMed verplichten om ‘combinaties van woorden’ als
zoekeenheid te beschouwen.
De woordcombinaties worden geplaatst tussen dubbele
aanhalingstekens: “…”
Ook dan wordt ‘Automatic Term Mapping’ afgezet.
UITVOERING van een zoekactie
PubMed interpreteert steeds elke zoekopdracht van
Rechts Links!
Zoeken naar één specifiek artikel

Zoeken naar artikels over een bepaald onderwerp!
Text-words
(“not weighted”)
MeSH-terms
(“interpreted and weighted”)
Text-words: examples
Physician – patient - interaction
? Interaction
Drug - interaction
? “This paper is not addressing Hepatitis C …”
? SMOKING (cessation?)
MeSH index
Major Topic Headings
Bevat slechts 2, maar wel de meest revelante (*)
headings die bij de publicatie passen
(*zoals gebruikt in Index Medicus)
Medical Subject Headings
(MeSH)
Example
“Car phones and accidents”
accidents, traffic AND telephone
-ALL categories
 Category A, B, C
 Subcategory
- Sub-subcategory
All Categories of Medical Subject Headings
Anatomy Category
BODY REGIONS
EXTREMITIES
ARM
AXILLA
ELBOW
FOREARM
HAND
FINGERS
THUMB
WRIST
SHOULDER
EXPLODE
MeSH index
 specify a search!
MeSH index

broaden a search!
EXPLODE
e.g.: “exploding ANGINA PECTORIS”
- Angina pectoris
- Angina pectoris, variant
- Angina pectoris, unstable
- Microvascular angina
Pubmed as interface automatically explodes parent terms
to include more specific child terms.
EXPLODE
: enkel ‘zwarte’ term
SUBHEADINGS or QUALIFIERS
- More than 60 categories (eg. disease, drug, …) with their own
list of possible subheadings.
“Powerful tools for sharply focusing a search”
 Searching under ASPIRIN alone in the MeSH index produced 4.985 citations over
the past five years.
 Of these 4.985 citations, 130 were also indexed under GASTROINTESTINAL
HEMORRHAGE in the MeSH index.
Adding subheadings sharpened the focus and narrowed the results:
 Searching under ASPIRIN with the subheading adverse effects applied to it,
produced 1138 citations in the MeSH index over the past five years.
 When these 1138 citations were limited to those that were also indexed under
GASTROINTESTINAL HEMORRHAGE with the subheading chemically induced
applied to it, the 88 most revelant citations were found.
LIMITS (Beperkingen)
Fields (alle of beperkt)
Alleen ‘met abstracts’
Publicatietype
Taal
Leeftijd
Geslacht
Human of Animal
Subset
Data
PREVIEW en INDEX
Stapsgewijze, op voorhand zoeken, hoeveel citaties
resulteren uit een zoekactie ‘in constructie’.
BEWAREN van een Search-String
• Naar het ‘DETAILS’-venster gaan en de URL opslaan als
bookmark of als favoriet (minder aangeraden).
• MyNCBI gebruiken (tot 100 zoekstrings opslaan!)
Voordeel:
checken voor nieuwe items sinds de laatste update
1. ‘zoekstring uit het verleden’ aanklikken
2. ‘what’s new for selected’ aanklikken
LIMITING STRATEGIES
(Example of a ‘standard’ approach)
1. Identify relevant Medical Subject Headings and
subheadings
2. Search on their intersection
3. Limit your results to:
- a specific journal
or - a publication type!
or - the Major Topic Heading
or - language = English
4. Read and examine
5. Refine your search
PUBLICATION TYPES
- describe the manner in which subject contents (cfr. MeSH)
are conveyed;
- frequently used PTs;
1. Practice Guideline
2. Clinical Trial
3. Randomized Controlled Trial
4. Letter
5. Review
6. Meta-Analysis
7. Editorial
Example: Hypertension
“How should one decide which drug(s) to prescribe
for high blood pressure?”
1. HYPERTENSION / DRUG THERAPY
MeSH
7449 citations
(5 years)
Subheading or
Qualifier
2. Practice Guideline [PT]
46 citations
Practice Guideline
Examples of Authoritative Committees:
- National Institute of Health (NIH)
- Agency for Health Care Policy and Research (AHCPR)
- American Diabetes Association
-…
Efficacy and Safety of Therapeutic Interventions
Associated Publication Types:
CLINICAL TRIAL (general)
CLINICAL TRIAL, phase 1: safety?
CLINICAL TRIAL, phase 2: therapeutic efficacy, dose range,
kinetics, …?
CLINICAL TRIAL, phase 3: safety + efficacy
CLINICAL TRIAL, phase 4: post marketing surveillance:
- adverse drug reactions
- patterns of drug utilization
CONTROLLED CLINICAL TRIAL: involving a control group
RANDOMIZED CONTROLLED CLINICAL TRIAL:
- an at random control group
“highest standard for scientific knowledge”.
MULTICENTER STUDY: to get larger samples
REVIEW
Publication Type “Review” often helpful:
- when not much is known about the subject
- for controversial issues
Example:
MeSH “obesity”  21.529 citations (/5Y)
Review [PT]
 4.379 citations (/5Y)
NEJM [TA]
 9 citations (/5Y)
META-ANALYSIS
“ is a quantitative technique for pooling the results
of many studies and re-analyzing the results“
Publication Type “Meta-Analysis” is a way to approach
a (controversial) issue that could not be resolved by single
studies (with sufficient power)
(relatively few)
EDITORIALS
“ are thoughtful appraisals of issues of importance written
by individuals with deep knowledge on the issue “
 editorials provide some of the most interested
reading in the medical literature!
PRACTICAL TIPS
1. Before doing anything (eg. connecting to MEDLINE),
take your time and ‘think’.
2. Browse on-line MeSH and be specific in framing your question.
3. Be inquisive and experiment with various approaches:
“effective searching is an iterative process that involves both
narrowing and widening strategies”.
4. Evaluate results (eg. when you find conflicting information).
5. Read beyond abstracts: abstracts are seductive! (cfr. bias);
full-text (incl. the discussion section) not in MEDLINE;
more and more on-line full-text versions on the Web.
6. NLM also produces other databases then MEDLINE focussing
on more specific knowledge (eg. BioEthicsLine …)
7. Keep track of what you have learned (cfr. Bibliographic
management software, eg. Prolite, EndNote, …)
NCBI Search Engine
is also using the PubMed search engine of MEDLINE and is a
gateway to other MEDLARS-databases (not exhaustive):
JOURNALS on the WEB
Publishers of Journals can offer:
- free full-text on-line access
- free access to selected articles
- full access to subscribers
- paid access (other mechanisms)
NLM maintains links to several hundred journals for
full-text access (cfr. Journals Database in PubMed)
HEALTH INFORMATION on the WEB
Cave: no standards for ensuring quality!
Links:
- http://www.healthfinder.gov/
- http://www.nlm.nih.gov/medlineplus/
-…