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]> 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
>Email: [log in to unmask]
>Website: http://evidence-based.urology.ufl.edu
>
>
>
>-----Original Message-----
>From: Evidence based health (EBH) [mailto:[log in to unmask]] On Behalf Of Declan Murphy
>Sent: Saturday, October 31, 2009 3:08 AM
>To: [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
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