RE: [NMusers] Reporting Modeling Results

James,

They were not removed prior to analysis, they were excluded immediately
after consent. Following consent it became apparent that they were not
eligible. Here is an example to help you follow the workings of a hospital.
A subject is recruited in the ER and given a dose of UFH which was not
charted immediately by the ER physician. The subject was consented, then the
UFH was written up by the physician prior to transfer to a medical ward. Now
they are ineligible, have never had the drug being tested and need to be
excluded according to the protocol. As such, you do not know what events
occurred because they were not in trial. So, they were not "retrospectively
excluded treated subjects" as they did not have the treatment.

Bruce


-----Original Message-----
From: owner-nmusers_at_globomaxnm.com [mailto:owner-nmusers_at_globomaxnm.com] On
Behalf Of James G Wright
Sent: Tuesday, October 30, 2007 11:37 AM
To: 'nmusers'
Subject: RE: [NMusers] Reporting Modeling Results

Steve,

Retrospectively excluding treated subjects from an RCT is a basic
methodological error (no matter who does it). Doing so casts very
fundamental doubts on the reported results. However, if these 4
exclusions didn't in fact bias the results of your study, then your
conclusions may still be correct.

Did any adverse events occur in the 4 excluded subjects in the novel
treatment arm? This is all I wish to know.

Best regards, James

James G Wright PhD
Scientist
Wright Dose Ltd
Tel: 44 (0) 772 5636914
www.wright-dose.com


-----Original Message-----
From: owner-nmusers_at_globomaxnm.com [mailto:owner-nmusers_at_globomaxnm.com]
On Behalf Of Stephen Duffull
Sent: 29 October 2007 20:21
To: 'James G Wright'; 'nmusers'
Subject: RE: [NMusers] Reporting Modeling Results


James

I had hoped we would move on :-)

> As you are holding up this enoxaparin work as a generalizable example,

It is just a single example - there are many others.

> I think your bold claims merit at least a token
> challenge. When I review academic studies, the first thing I check for

> is patients who are excluded from the data analysis.

I am absolutely astounded that you consider academic studies in a more
critical light than industry driven studies. Shouldn't all studies be
taken on their merit - or are you suggesting that academic studies are
naturally flawed in some way?

> Did excluding these 4 subjects alter the results of the trial?

Simply the patients were removed before analysis. They did not meet
protocol requirements (e.g. some received unfractionated heparin).

It is my best belief that if we continued to recruit patients that we
would see the same signal as the trial found. The trial was adequately
powered so we are not expecting bias inherent in underpowered studies
(compare to the underpowered APPROVe study wrt CVS observations).

In addition, the purpose of this part of the thread, for me, was to show
that a) studies do arise in academic settings that improve patient care
[to respond to Mark's comments] and b) that simplifying the dosing on
the drug label to make the drug "easier to use" doesn't necessarily
result in better patient outcomes.

Regards

Steve
--
Professor Stephen Duffull
Chair of Clinical Pharmacy
School of Pharmacy
University of Otago
PO Box 913 Dunedin
New Zealand
E: stephen.duffull_at_otago.ac.nz
P: +64 3 479 5044
F: +64 3 479 7034

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Received on Mon Oct 29 2007 - 22:42:02 EDT