PubMed & Impact Factors
Summerschools 2013 Pediatrics & NeuroScience UMCG
Central Medical Library July 9th 2013
Your teachers this afternoon
Guus van den Brekel & Hans Froon
Email: [email protected]
Website library: http://www.rug.nl/umcg/library
Content
1. Finding Best Evidence and PubMed• Excercises• feedback
2. Impact Factors, H-Index, Top 25% ..• Excercises• feedback
Finding best evidence & PubMed
PICO approach & ExamplesPubMed Tutorials:
From NLM: http://www.nlm.nih.gov/bsd/disted/pubmed.html•Intro (What is PubMed), •term mapping, •Boolean operators, •MeSH, •textwords, •filters
PICO(S)
P : Patient or problem
I : Intervention (or risk factor, prognostic factor)
C : Control group (or absence of risk factor, progn.factor)
O : Outcome
(S): Study type
Categories: therapy, diagnosis, etiology, prognosis
Example 1
A 30 year old man attends the
emergency department after having
been bitten by a dog 4 hours
previously. He has puncture wounds
and a 1 cm laceration on his forearm.
His wounds are thoroughly cleaned and
a dressing has been applied.
Question: Do you need to prescribe
antibiotics?
PICO(S) example 1:
P = (adults with) dog bites
I = antibiotics
C = no antibiotics/ placebo
O = incidence of wound infection
S = randomized controlled trial
•Find search terms and synomyms for every section when needed
•Build your search strategy with Boolean operators
PICO(S) example 1:
T
• Dog bite antibiotics
• (dog OR dogs) AND (bite OR bites) AND (antibiotic OR antibiotics OR penicillin)
Boolean Operators (AND, OR, NOT)
Example 2
An 5 year-old child has crashed on his bicycle into a
car.
He suffers from abdominal pain, caused by his bike’s
handlebar which thumped into his abdomen.
Question: What is the value of a CT-scan compared
to echography in case of a child with blunt (non-
penetrating) abdominal trauma?
PICO(S) example 2
P = child blunt abdominal trauma
I = CT
C = echography
O = (diagnostic value)
(S) = (diagnostische studies)
Exercises Finding Best Evidence
1. You are interested in the effectivity of interventions (such as cognitive therapy) aimed at the prevention of major depression recurrence/relapse. P = I = C = O = Type of article:
Exercises Finding Best Evidence
2.For adolescents with OCD (obsessive comp. Disorder), which treatment is more effective to start with: cognitive behaviour therapy, an anti-depressive agent (SSRI) or a combination of both treatments? P = I = C = O = Type of article:
Exercises Finding Best Evidence
3. Many babies that are breastfed sleep regularly part of the night in the bed of their parents. Since a couple of years this is strongly discouraged in guidelines to prevent cot death (Sudden Infant Death Syndrome). Can you find evidence that sleeping between the parents is a risk factor for SIDS?P = I = C = O = Type of article:
Feedback & Questions
Top 25%, Impact Factors and h-index
List top 25% journals per ISI category http://atumcg.cmb.med.rug.nl
CMB-website: www.rug.nl/umcg/library
Impact Factor
Measure for number of citations to a journal over a certain period of time
Quality?
1975- now : Journal Citation Reports
MOLECULAR IMMUNOLOGY
Cites in 2008 to articles from 2007 resp 2006: 1143 + 800 = 2243 cites
Number of articles in 2007 resp 2006: 407 + 224 = 631
Impact Factor: 2243/ 631 = 3.555
Value
Depends on ISI “Subject Category” view journal summary list
Top 25%
MOLECULAR IMMUNOLOGY
1st Category: BIOCHEMISTRY & MOLECULAR BIOLOGY
Ranking based on impact: 89 / 275 = 0.32 (history)
2012 Ranking: 161 / 290 = 0.55
Outside top 25%
MOLECULAR IMMUNOLOGY
2nd Category: IMMUNOLOGY
Ranking based on impact: 35 / 121 = 0.29 (history)• 2012 Ranking: 81 / 135 = 0.60
Also outside top 25%!
Positive
broad spectrum (9000 journals, 60 countries)
objective (quantity) worldwide known
negative
limited to ISI journals
subject category dependentComparing IFsDisadvantage specific research area
influence of “spikes”
Manipulation
IF does not say anything about individual article
Other measures of impact
Journal Immediacy Index (ISI)
Journal Cited Half-Life/ Journal Citing Half-Life
EigenFactor & Article Inluence Score (ISI) www.eigenfactor.org
SCImago Journal & Country Rank (Scopus) www.scimagojr.com
Output scientists
bookchapters, thesis patents conference proceedings articles in peer-reviewed journals
number of publicaties (in top 25%)
citations, citaties per article
Hirsch-index
Impact authors: citation analysis
Citation analyse
the number of publications the number of publications in top 25% (in relevant ISI-subject categories) the number of citations h-index …
Databases
Peer reviewed literature:
Web of Science (SCI + SSCI)– Thomson ISI (Scopus - Elsevier) Medline - NLM Embase - Elsevier
coverage>99.9%
Other:
Repository RUG: thesis researchers /PiCarta: book chapters
Databases for citation analysis
Web of Science– Thomson ISI
Scopus – Elsevier (no access anymore)
Access via CMB website: http://www.rug.nl/umcg/libraryAccess to full text & databases from home:Use your S-number or guest account
prof. dr. D.S. Postma
Web of Science (author search)
Postma DS: 587 hitsExcluded: meeting abstracts, notes, corrections
511 hits (=articles, reviews, editorials, letters, proceeding papers)
prof. dr. D.S. Postma
Web of Science (advanced search)
#1 (AU=Postma DS) AND (OG=gron* OR OG=beatr*) 529 hits#2 AU=Postma D AND TS=(immu* OR asthma* OR lung* OR resp* OR pulm*) AND (OG=gron* OR OG=beatr*) 23 hits#3 (#1 OR #2) 552 hits
Excluded: meeting abstracts, notes, corrections
480 hits (=articles, reviews, editorials, letters, proceeding papers)
Difficult author names
Multiple initials“Tussenvoegsels”, insertionName changes (marriage)Common names
Voorbeeld: prof. P.E. de Jong de Jong PE; Dejong PE; Jong PED; de Jong P
H-index
J.E. Hirsch (2005)
H-index = n:author has n publications with n citations or more
Power: less influence spikes
Publishing a lot is not rewarded, but the publishing of
many higly-cited publications is!
Other interesting links
• Google Scholar http://Scholar.google.com
• Publish or Perish (PoP): http://www.harzing.com/pop.htm
• AltMetrics : alternative metrics for impact: http://altmetrics.org/manifesto/
• 10 Ways to calculate your H-Index : free and otherwisehttp://digicmb.blogspot.nl/2013/06/ways-to-calculate-your-h-index-free-and.html
Excercises
Exercise 1: Impact Factor
You are working on a systematic review on the prevention of obesity in young children. You consider to send your your manuscript to the Int J Pediatr Obes.
•What is the impact factor? •Is it top25%? •What are the ISI fields of this journal? •What would be a good alternative (journal)?
Published papers by Simone Times Cites
paper 1 (2012) 0
Paper 2 (2012) 1
Paper 3 (2011) 3
Paper 4 (2010) 5
Paper 5 (2010) 1
Paper 6 (2010) 0
Paper 7 (2009) 15
Paper 8 (2008) 3
Exercise 2: h-indexA young researcher, Simone, has 8 publications. One of her papers, a review, has been cited 15 times. The sum of the times cited is 28. What is the h-index of Simone?
Exercise 3: publication and citation overview
Prof. D. Postma is a respected researcher at the department of Pulmonology. Her initials are DS (Dirkje S. Postma).
•How many publications of prof. Postma (in combination with the address field – Groningen) are found in WOS/WOK? •What is the corresponding h-index?
Compare this to the number of publications in Scholar Google.
Feedback & Questions
A little extra!
Make life easier!
Use Journal Apps to keep up with the literature.
BrowZine | Docwise | Read by QxMD
Read more: http://libguides.rug.nl/medicalEjournals