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: cmb@umcg.nl

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