Dear Lilya,

I would agree with you.

Attached is a powerpoint presentation that I use to critically appraise cohort studies and if I go by that presentation and what Declan has mentioned in his emails, this is definitely NOT an inception cohort study.

Regards,

Ash

Dr Ash Paul
Medical Director
NHS Bedfordshire

21 Kimbolton Road

Bedford

MK40 2AW

Tel no: 01234795705

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From: Liliya Bakiyeva <[log in to unmask]>
To: [log in to unmask]
Sent: Sun, 1 November, 2009 10:16:23
Subject: Re: Inception cohort study and level I evidence

I hope others will correct me if I am wrong, but I am inclined to think that the surgical case series evaluating the outcome of the operative intervention is NOT an inception cohort. It is especially difficult to claim it was an inception cohort if the procedure was modified along the way. If we formulate the PICO question, then we will have P=cancer patients I=Surgery C=well, nothing I could say based on the information provided by Declan and O=survival rates. Since the object of the evaluation is the therapeutic intervention (surgery), I would tend to believe this is a therapy study, for which the Gold Standard is, of course, RCT.

2009/11/1 Cristian Baicus <[log in to unmask]" target=_blank rel=nofollow ymailto="mailto:[log in to unmask]">[log in to unmask]>

In an inception cohort, the patients are included at the beginning of the disease which prognosis we want to study. Sometimes we cannot know when the disease started, so we include patients when the disease is diagnosed.
If the question refers to the prognosis of opperated patients, then we know when the disease begun (with the operation), so this really was an inception cohort.

Cristian Baicus

dr. Cristian Baicus
Spitalul Colentina
Clinica de Medicina Interna
020125 BUCURESTI
Romania
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www.baicus.ro

----- Original Message ----- From: "Declan Murphy" <[log in to unmask]" target=_blank rel=nofollow ymailto="mailto:[log in to unmask]">[log in to unmask]>

To: <[log in to unmask]" target=_blank rel=nofollow ymailto="mailto:[log in to unmask]">[log in to unmask]>
Sent: Sunday, November 01, 2009 8:31 AM
Subject: Re: Inception cohort study and level I evidence

Dear Colleagues,
Many thanks for all your expert comments on this topic. This has been most helpful.
The paper I am reviewing is a consecutive surgical series with accrual of patients from 2001-2008. The intervention is a surgical procedure and the primary outcome relates to cancer cancer recurrence and survival.
My question is does this constitute an inception cohort study? Excuse my ignorance of this definition but this is not a commonly applied methodology in surgical series. What is described in this paper appears to be a consecutive case series and a number of other papers have been published from this in the past six years. My understanding was that an inception cohort was a group of patients assembled at the start of a study period and followed throughout. If patients are continuously accrued then like is not being compared with like, especially as the authors have published a number of modifications to the intervention over the past eight years which could clearly have an impact on outcomes.
Once again, I am grateful for your expert comment!

Regards

Declan

Mr Declan G Murphy FRCS Urol
Consultant Urologist
The Urology Centre
Guy's Hospital
St Thomas' Street
London
SE1 9RT

Tel: +44(0)7880 731254
www.gstt.nhs.uk/urology
www.youtube.com/decmurphyurology

On Sat, 31 Oct 2009 12:56:17 -0400
"Dahm, Philipp" <[log in to unmask]" target=_blank rel=nofollow ymailto="mailto:[log in to unmask]">[log in to unmask]> wrote:

Dear Declan:

Interesting to see a query from the urological literature; this may be the first time.

As stated by others previously, the CEBM grading system considers high quality evidence from inception cohort studies as level I evidence for questions of PROGNOSIS. I'd make sure though that what you are looking at is not a surgical case series and that the question is indeed one of prognosis (not therapy).

I'm afraid I'd place relatively little stock in the authority of the authors or the journal....

Happy to discuss further off-line. Always keen to meet other urologists interested in EBM!

Greetings from Florida.

Ph*

Philipp Dahm, MD, MHSc, FACS
Associate Professor of Urology, Associate Residency Program Director & Director of Clinical Research
Department of Urology
University of Florida
College of Medicine, Health Science Center
Box 100247, Room N2-15
Gainesville, FL 32610-0247
Phone: (352) 273-7936
Fax: (352) 273-7515
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Website: http://evidence-based.urology.ufl.edu

-----Original Message-----
From: Evidence based health (EBH) [mailto:[log in to unmask]" target=_blank rel=nofollow ymailto="mailto:[log in to unmask]">[log in to unmask]] On Behalf Of Declan Murphy
Sent: Saturday, October 31, 2009 3:08 AM
To: [log in to unmask]" target=_blank rel=nofollow ymailto="mailto:[log in to unmask]">[log in to unmask]
Subject: Inception cohort study and level I evidence

Sorry to bother you guys with a query. I am reviewing a paper which claims to be CEBM Level Ib as it is an "inception cohort study with over 80% follow-up". It is not an RCT, it is simply a large surgical cohort followed prospectively for a few years and the data is not comparative in any way. Seven or eight papers have been published from this series previously but this is the first time they have claimed level Ib evidence status. Is it appropriate for the authors to claim this is Level Ib evidence and to reference the CEBM in support? The authors are well known in urology and this paper is under submission to the leading urology journal so I am anxious to ensure they are not discrediting the CEBM levels with this claim.
I would very much appreciate your advice.

declan

Mr Declan G Murphy FRCS Urol
Consultant Urologist
The Urology Centre
Guy's Hospital
St Thomas' Street
London
SE1 9RT

Tel: +44(0)7880 731254
www.gstt.nhs.uk/urology
www.youtube.com/decmurphyurology
dr. Cristian Baicus
Spitalul Colentina
Clinica de Medicina Interna
Sos. Stefan cel Mare 19-21
sect. 2
020125 BUCURESTI
Romania
Mobil: 0788302355
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www.baicus.ro

--
Liliya

"Eternity is a mere moment, long enough for a joke." - Hermann Hesse