Rachel,
Also bear in mind that some investigators are not entirely clear what randomization means. Some authors of trials do not know that a randomized trial of a therapy infers that patients were prospectively randomized at entry to the study to treatment group(s) versus comparator group(s).
I have encountered examples in the literature where the authors reported their trial was "randomized", but they did not mean a randomized controlled trial was performed. They had randomly chosen patients (either prospectively from a willing population, or retrospectively from a database), and analyzed them as treatment and control groups.
But, the key difference between this falsely stated "randomization" and a true randomized controlled trial is that a truly randomized controlled trial relies on random assignment of patients at the time of study entry to treatment vs control.
Any of the following would be a clear sign that a trial was not a true randomized controlled trial:
1. If assignment of patients to treatment or control was not performed by a random generator or flip of a coin, but rather was CHOSEN by the investigator or the physician taking care of the patients, or
2. If there was no comparison group.
3. If the trial was retrospective.
I also agree with Bill Grant, that it is safest to contact the authors to clarify.
Thanks,
Janet
Janet Martin, PharmD, MSc(HTA&M)
Co-Director, Evidence-Based Perioperative Clinical Outcomes Research Group (EPiCOR)
Director, HiTEC
Coordinator, Pharmacy Services
London Health Sciences Centre, University Hospital
Assistant Professor, Department of Anesthesia & Perioperative Medicine
University of Western Ontario
Tel: 519-685-8500 x35882
Email: [log in to unmask]
Sent from wireless handheld device.
-----Original Message-----
From: William Grant <[log in to unmask]>
To: <[log in to unmask]>
To: Grant, William <[log in to unmask]>
Sent: 3/13/2009 10:19:33 AM
Subject: Re: Research Study Design
Rachel:
With all due respect, if you are conducting a systematic review it is
important to get the details correct.
Rather than speculate, I suggest you track down the authors and ask them
directly your question regarding
the use of control groups. They are in the best position to answer your
questions.
And, until you sort this all out, you won't be able to determine the
appropriate analysis.
Bill
>>> Cristian Baicus <[log in to unmask]> 3/13/2009 10:07 AM >>>
Even the term "randomized" implies a control group, as one cannot randomize
in the absence of a control group!
Cristian
dr. Cristian Baicus
Spitalul Colentina
Clinica de Medicina Interna
Sos. Stefan cel Mare 19-21
sect. 2
020125 BUCURESTI
Romania
Mobil: 0788302355
[log in to unmask]
www.baicus.ro
----- Original Message -----
From: "Jeremy Howick" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, March 13, 2009 2:24 PM
Subject: Re: Research Study Design
Dear Rachel,
A randomized controlled trial is, by definition, controlled
(www.cebm.net/?o=1116). So, either the authors of the study have used the
term 'RCTs' incorrectly (unfortunately this does happen), or they have not
explained what the control group is clearly and you have overlooked it.
I hope this helps.
Best wishes,
Jeremy
Jeremy Howick, PhD
Centre for Evidence-Based Medicine
Rosemary Rue Building
Old Road Campus
University of Oxford
Oxford OX3 7LF
United Kingdom
tel: +44 (0) 1865 289 363
fax: +44 (0) 1965 289 336
>>> Olive Goddard <[log in to unmask]> 03/13/09 11:26 AM >>>
Dear Colleagues,
If you can help Rachel I should be grateful if you would respond to her
directly (or copy her in to the response).
All good wishes,
Olive
Olive Goddard
Centre and Editorial Manager
Centre for Evidence-Based Medicine
Department of Primary Health Care
Old Road Campus, Headington
Oxford, OX3 7LF
.....................................................................
Tel: +44 (0)1865 289337 email: [log in to unmask]
Fax: +44 (0)1865 289336 web: www.cebm.net
Mobile: 07804 625002 web: www.cebmh.com ( http://www.cebmh.com )
>>> Rachel Scarisbrick <[log in to unmask]> 13/03/2009 07:29 >>>
Hello
I am just asking for your advice surrounding a research study design. I am
performing a systematic review on a number of articles which investigate
the
effect of a neuromuscular training versus a traditional strength training
protocol in ACL injured individuals.
The studies state to be randomised control trials however as no control is
present is this correct or should they be termed randomised comparative
trials? Also what appraisal tool can be used with these studies?
Thank you in advance
Rachel
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