Why do we do systematic reviews? The final poll

Voting is over in the second poll asking ‘Why do we do systematic reviews?’  I re-ran the poll as I felt the questions could have been better worded from the first one!  So, the results:

  1. To see what has been done before, to see if new research is needed and/or to learn from previous research – 29.31% (27.35%)
  2. To quantify, quite tightly, how good an intervention is – 23.56% (23.32%)
  3. To simply know if an intervention is effective relative to placebo or an alternative intervention – 22.99%
  4. To understand the adverse events associated with an intervention – 14.37% (17.04%)
  5. Because the research funders insist on it before considering funding – 5.17%
  6. To improve career prospects – 4.6% (7.62%)

NOTE: The figures in brackets are from the first poll. I have included only those where the meaning is similar.  Also, I used different sampling methods for both.  The first I used the website and social media.  The second poll also included a mailshot to the registered Trip users.  The results seem broadly consistent.

I have commented on nearly all the above reasons previously:

  1. To see what has been done before.
  2. To quantify, quite tightly, how good an intervention is.
  3. To simply know if an intervention is effective.
  4. To understand the adverse events.
  5. Career prospects.

So, lots of effort and lots of participation from a variety of people – but to what end?  The motivation of this series was a view I had that people undertake systematic reviews with little explicit reason.  Sure, they may want to know if Drug A is useful in condition Z – but for what purpose?  Are they planning new research, do they really need to know how effective the drug is or simply know if it’s better than placebo??

Once these questions are answered you can start to better explore the appropriate method.  For instance, if you need to know – very accurately – how good an intervention is, the standard (Cochrane-style) systematic review is simply not robust enough. So, if you’re actually happy with a ball-park estimate then do it quickly.

Let the method be led by the desired outcome, one size (method) does not fit all! We really must be more sophisticated in our thinking around the procurement of systematic reviews.  Being more explicit about the real reasons for the review are important as is another strand, the notion of Value of Information inextricably linked.

This theme will continue, I have no doubt…!



2 thoughts on “Why do we do systematic reviews? The final poll

  1. As I have never done a systematic review, I could not answer the poll. The ultimate reason for any health research, including a systematic review, is to improve healthcare for patients, but that wasn’t on the list of options. Why systematic reviews seem to have become a “special case” and an end in themselves, I cannot fathom. Systematic reviews *could* be most useful in guiding new research (to improve healthcare) because most (if not all) reviews reveal that previous research is flawed, incompletely reported or unavailable. A new “species” of review explicitly linked to the purpose of improving future research could include a template protocol, based on any well conducted and relevant studies, involving patients in the study design and choice of outcomes, and reported using existing guidelines such as SPIRIT.


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