G'day!
The line between fully systematic and all other reviews isn't a precise one, but I don't think the issue of just searching trials at registry agencies is a viable alternative as a methodology. Firstly, not all questions are even relevant here (not every clinical question is about a drug or device). Secondly, regulatory agencies do not try to keep their dossiers up-to-date for every drug or device - especially for trials that aren't sponsored by the manufacturer.
We faced the same kinds of issues when we started to look at how much work you have to do for an update. And the problem is, we still don't know how to predict which are the ones for which less work will be the same as more work. It's a minority of cases where being less systematic will make an important difference and so it's not hard to find samples where it made no difference. The key question it seems to me is to know prospectively when being more systematic will make a difference. At least some way of narrowing this down will likely emerge through the work of the health technology assessment agencies.
Hilda
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From: Jon Brassey [[log in to unmask]]
Sent: Wednesday, March 20, 2013 6:15 AM
To: [log in to unmask]
Subject: Reviews
Hi All,
You may remember I asked about the purpose of systematic reviews the other month. I'm still trying to understand the area and one connected area is that of language. We say 'systematic reviews', 'rapid reviews' etc. But these are just umbrella terms which can be helpful and can also mis-lead.
Take the term systematic review (SR) - as we all know there are many different methods. A recent big contrast is between those that use regulatory data and those that don't - yet they are both SRs. If you examine the work of Tom Jefferson on Tamiflu the difference between his SR without regulatory data (his initial Cochrane review) and with (the follow-up Cochrane SR) the difference was profound. So, I can't help feeling the term is unhelpful - other than broadly indicating that the review was long/timely etc.
Then, an area I've been looking at the literature on, rapid reviews. These are less in-depth than SRs but I dare say the results are broadly comparable. Finally, the world I'm actively involved in 'ultra rapid reviews' - what are they? To me they are reviews done in a couple of days maximum.
So, to my mind, these terms are not hugely helpful - am I alone in that?
I wonder of there is a wider need to codify things? So, you could break it down for each component e.g. search. This could range from searching a single database through to multiple databases and the 'ironman' being using regulatory data? You could do that for all the components.
What would then be helpful would be to compare the results of each different component on the subsequent end-point. You could then make a reasonable estimate of the cost-benefit of moving up to the next stage of search, appraisal, synthesis etc.
Any thoughts?
BW
jon
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Jon Brassey
Trip Database
http://www.tripdatabase.com
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