manuscript writing and assessment marko turina … · manuscript writing and assessment marko...

MANUSCRIPT WRITING AND ASSESSMENTASSESSMENT

Marko TurinaUniversity of Zurichy

Switzerland

This is an interactive session; be free to interrupt and ask questions at any time duringquestions at any time during

the talk!

You have collected the data and would like to write a manuscript: how to proceed?write a manuscript: how to proceed?

First, analyze your data carefully: the essence of i i h l i D i l l dscience is the analysis. Do not simply unload

your data into tables and figures, add text and send it somewheresend it somewhere.

“Observations are useless until they have been Obse at o s a e use ess u t t ey a e beeinterpreted. The analysis of experimental data forms a critical stage in every scientific inquiry – a stage which has been responsible for most of the foolishness andhas been responsible for most of the foolishness and fallacies of the past”

E. Bright Wilson, An Introduction to Scientific gResearch.

Rule Nr. 1: Do not over-interpret and over-extrapolate your dataextrapolate your data

Where to send the manuscript?

• Circulation, JACC, NEJM, JAMA have very high impact factor and accept < 8 % of submitted manuscripts: only the very best material qualifiesmanuscripts: only the very best material qualifies.

• JTCVS, Annals and EJCTS have similar impact factor; acceptance rate is ~ 25-30 %p

• Papers presented at annual meeting of large associations have somewhat better chance of acceptance because congress material shouldacceptance, because congress material should be published.

• Focused work (TX, assist devices, cell t h l ) h b tt h i i li dtechnology) has better chance in specialised journals: JHLTPL, ASAIO journal, Cell, Nature, etc.

Start your work by carefully reading instructions forreading instructions for manuscript submission

EJCTS instructions for manuscript submission

A word of caution about theA word of caution about the dictate of statistics in today's science (not to be interpreted as speaker’s backwardness)as speaker s backwardness)

Do not be misled by statistical associations: they b l t lcan be completely erroneous

Beware of multiple subgroup analysis!!

Courtesy of Pieter Kappetein, EACTS

Circulation 1980; 61(3):508-15

Simple rules which researchers should remember when attacking their data with some massive statistical effortattacking their data with some massive statistical effort.

• Statistical end result (p value, Χ2) shows only the degree of association; it says nothing whatsoever about causal relationship (“Torture the data until they confess….”).B f “P h h ” l i l• Beware of “Post hoc, propter hoc” logic: temporal relationship of two variables (one occurring after the other) does not mean that it is a “cause and effect”other) does not mean that it is a cause and effect relation.

• With large hospital data banks now required by law inWith large hospital data banks now required by law in many countries, “data mining” can be very productive, but this is not science: results can be valid only if a previously determined hypothesis is being evaluated.

Nevertheless, the rules about t ti ti i ’ ti i tistatistician’s participations are

clear in most journalsclear in most journals

JTCVS rules

Watch your numbers when writing manuscript!

From a recently submitted manuscript (it was rejected)

Check your English when writing manuscript!What is “idoneous”?

For authors who are not native English speakers, it is a good practice to elicit help from expert translator/assistantg p p p

Check your English when writing manuscript!Avoid strange abbreviations!

Try to avoid abbreviations: they make your manuscript difficult to read, and are usually

unnecessary”Cardioplegia (C) is a type of ischemia-reperfusion injury (IR),

ll it i t d ith h th i (H) IRusually it is connected with hypothermia (H). IR causes myocardial stunning (MS). MS occurring after IR has been extenisively investigated, both the metabolic consequences (MC), the gene programs (GP) activated, the ione shifts (IS) occurring, etc. ”

“The role of MC GP and IS in C induced IR is not fully knownThe role of MC, GP, and IS in C-induced IR is not fully known, neither are the exact cellular events of MS. HCA is important to protect the heart”Did Tolstoy use abbreviations in ”War and Peace”?

Did Hemingway use abbreviations in ”The old man and the sea”?

After Jarle Vaage, Prague 2008

Some remarks about p-valuep• What is the real difference between p=0.046 and

p=0.054?• Beware of the distinction between “Significant/

non-significant”, vs. “Clinically relevant”• Don’t present your p-values as either p<0.05 or

S (f f ) GNS (for non-significant): Give exact p-values and let the reader evaluate the importanceA t bl 0 001 d 0 2 i b t i• Acceptable: p<0.001 and p>0.2, in between give exact p-values like: p=0.006, p=0.027


In statistics, use numbers which were actually measured, not calculation-derived artifacts. This

error is surprisingly common in many submissions.

Do not write:Do not write:• Cardiac output was 5.389 ± 0.439 L/min• Blood pressure increased from 138.916 ± 31.937 …p• Positive effect was observed in 55.6 % of patients …• Avoid percentages in small numbers (< 30)

Instead, use:• Cardiac output was 5.4 ± 0.4 L/minCa d ac output as 5 0 /• Blood pressure increased from 139 ± 32 …..• Positive effect was observed in 5/9 patients.


Honest use of error barsHonest use of error bars• Using SEM is a cheap trick, because it depends

th b f b ti d d ton the number of observations, and does not give proper information on variability.

• SEM = SD divided with the square root of the• SEM = SD divided with the square root of the number of observations, for instance: N=49, SD=14, then SEM = 14:7 = 2SD 14, then SEM 14:7 2

• SEM may sometimes be used in figures with longitudinal data and several groups to avoid too g g pmuch overlap.


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Which data will probably show i i ll i ifia statistically significant difference?difference?

1 Upper left one Press 11. Upper left one Press 1

2. Lower right one Press 2g

3. Impossible to tell Press 3

Refrain from statistical tricks: same data with SEM on the left with 95 % confidence limits on the righton the left, with 95 % confidence limits on the right.

mean ± SEM mean ± 95% confidence intervals

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When dealing with small numer of observations, use scatter plots and median valuesuse scatter plots and median values

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Beware of two deadly sins inBeware of two deadly sins in scientific publishing:

PlagiarismPlagiarism

Redundant (duplicate) publicationpublication

By all means, avoid plagiarism: reviewers are experts, and we have electronic means of detecting duplicate submissions or “borrowed” material. Avoid “Copy and Paste” technique even from your own material: it canAvoid Copy and Paste technique, even from your own material: it can easily become a duplicate publication!

Simple plagiarism check with Google Scholar from a recent publication

Simple plagiarism check with Google Scholar: Quick results

In US, plagiarism is a punishable offense, with a governmental agency supervising research and takinggovernmental agency supervising research, and taking

administrative actions.

Beware of two deadly sins inBeware of two deadly sins in scientific publishing:

PlagiarismPlagiarism

Redundant (duplicate) publicationpublication

EJCTS instructions for manuscript submission

All 6 conditions must be met to declare a publication as a duplicate one.

Definition of duplicate publication is well known, so avoid it!

Th bli ti ill b id dThe publication will be considered as duplicate, or redundant, when:

• Hypothesis is the same or similar.• Methods are identical.• Case material is similar, or somewhat

largerlarger.• Results are identical, or nearly so.

S l th t b th• Several authors are common to both publications.

Another bad practice is “Salami publishing” or “Parma manuscripts” (thinly slicedor Parma manuscripts (thinly sliced

material)

Your data should be submitted fully; do not try to send a part of it to one journal and the other part to another one. Editors talk to each other, and they meet often; so this action will be detected and will give you a black eye asbe detected, and will give you a black eye as author. This particular practice is often used to inflate author’s publication list; but it isto inflate author s publication list; but it is detested by editors because it burdens journals with similar material.

Rules for manuscript submission in EJCTSp

Rules for manuscript submission in Annals of Thoracic SurgeryThoracic Surgery

Rules for Annals of Thoracic Surgery: editors t i i lit !want originality!

Authorship rules are nowadays very strict: no h th hi !more honorary authorships!

Manuscript’s authorship: some advices

• Settle all authorship problems before beginning to g gwrite the manuscript: you will save yourself a lot of trouble later.

• First author is the researcher who performed most of• First author is the researcher who performed most of the work, and/or wrote most of the manuscript.

• Senior author is acknowledged to be the originator of g gthe idea/hypothesis, or in charge of the group submitting the manuscript.Having performed some or even a large part of• Having performed some or even a large part of surgeries described in the manuscript does not necessarily qualify for authorship, unless other criteria are met.

What not to do when submitting a manuscript

• Start discussion with the editor to be exempted from the journal’s rules (number of authors or literaturethe journal’s rules (number of authors, or literature citations, or word count - because you are obviously so important). You will quickly find yourself in the possession of your returned manuscript.

• Explain that a similar version has been presented elsewhere or has already been published but youelsewhere, or has already been published, but you added some patients/experiments/numbers. Editors want originality for their journals.

• Unsuccessfully disguise previous rejection of the same material (e.g. send “Ultra Mini-Abstract” to EJCTS – where it is needed only in JTCVS)EJCTS where it is needed only in JTCVS)

A d i tA good manuscript concentrates on essentials,concentrates on essentials,

and avoids long-winded l tiexplanations.

The best way to be boring is to leave nothing out.

Voltaire (1694 -1778)( )

This is an example of a good “Introduction” section

What is the lesson here? YouWhat is the lesson here? You can win Nobel prize for medicine

ith 3 ½ ti l ith 15with a 3 ½ pages article, with 15 references.

So, make your manuscripts short, containing only essential detailscontaining only essential details.

Avoid verbiage!

How to shorten the manuscript?

• Standard methods (e.g. cannulation, cardioplegia statistics etc ) can be shortlycardioplegia, statistics, etc.) can be shortly mentioned, and referenced (as previously described in # …, or according to Guidelines i # )in # …).

• In discussion, mention only the most relevant, recent papers Do not start with 200 BC etcrecent papers. Do not start with 200 BC, etc.

• Larger amount of numerical data belongs to tables and figures; in text you only comment g ; y ythe data.

• Avoid duplication: either text, or figures and t bl t b thtables; not both.

Highest chance of successful submission• Properly designed prospective randomized study

(double blind is next to impossible in surgery).• In non-randomized trials apply proper statisticalIn non randomized trials apply proper statistical

methods (e.g. propensity score, matching pairs). Statistician must be consulted, and he is one of the authors!authors!

• Meta-analysis is assuming increasing importance, but it is difficult to perform properly (selection of papers to be analyzed!)be analyzed!).

• Innovative work has a high chance of acceptance: new techniques, ideas, experimental observations.

• Manuscripts which question an established belief or a widely presumed “fact”.

• Novel classification or guidelines: this guaranteesNovel classification or guidelines: this guarantees highest citation index in a short time.

fEvaluation of session

Manuscript submission session was:• Good exercise (#1)• Somewhat useful (#2)( )• Waste of time (#3)

manuscript writing and assessment marko turina … · manuscript writing and assessment marko...

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