Unpublished studies in stem cells

I spotted an interesting tweet earlier and replied, the exchange is below: The paper in question is: Responsible Translation of Stem Cell Research: An Assessment of Clinical Trial Registration and Publications. For fear of being repetitive reporting bias is hugely problematic.  Avoiding unpublished trials can massively affect a systematic review [1, 2]. Yet Cochrane, arguably the ‘gold standard’ for systematic review production, has an unsystematic … Continue reading Unpublished studies in stem cells

Grey literature in systematic reviews

Grey literature in systematic reviews: a cross-sectional study of the contribution of non-English reports, unpublished studies and dissertations to the results of meta-analyses in child-relevant reviews. Hartling L et al. BMC Medical Research Methodology 2017 17:64 Conclusion: The majority of SRs searched for non-English and unpublished studies; however, these represented a small proportion of included studies and rarely impacted the results and conclusions of the review. … Continue reading Grey literature in systematic reviews

Sampling in evidence synthesis

One of the main criticisms of ‘rapid reviews’ is that they cuts corner (relative to systematic reviews) and therefore it makes the likely to be – in some way – ‘wrong’ (however that is defined).  This negativity is often taken from the perspective that a full systematic review is – in some way – ‘right’ (again, however that is defined). What is increasingly clear to me … Continue reading Sampling in evidence synthesis

The nature of evidence synthesis

Evidence Live has come and gone and I had a wonderful chat with Iain Chalmers.  Iain is a marvel and in the course of the conversation I had a ‘light bulb’ moment relating to the nature of rapid versus systematic reviews.  I’m increasingly unhappy with the distinction and I am of the view that the debate should not be ‘rapid’ versus ‘systematic’ but how, for a given context, can … Continue reading The nature of evidence synthesis

BMJ Clinical Evidence Blog: The Rise of Rapid Reviews

I was recently asked to write a blog article for the BMJ’s Clinical Evidence Blog, so I did… “Perfect is the enemy of good” Voltaire Rapid reviews are becoming increasingly commissioned, used and written about. But why is there this, relatively sudden, interest? Putting it bluntly, it’s because the cornerstone of evidence synthesis, the systematic review, is becoming increasingly out of touch with the needs … Continue reading BMJ Clinical Evidence Blog: The Rise of Rapid Reviews

Different approaches to rapidity

I have been reflecting that many of the approaches towards rapid reviews start with the notion of a systematic review and approach rapidity by removing bits. For example they may search fewer databases or perhaps only have one person assessing for bias.  But the principle is that the person undertaking the review (and those commissioning it) believe that the approach will not affect the result … Continue reading Different approaches to rapidity

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: 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%) To quantify, quite tightly, how good an intervention is … Continue reading Why do we do systematic reviews? The final poll

All in the Family, a follow-up

In an earlier post I highlighted the editorial ‘All in the Family: systematic reviews, rapid reviews, scoping reviews, realist reviews, and more’.  In the editorial the authors raised the issue of systematic reviews being a family and rapid, systematic, scoping were all part of the ‘evidence synthesis’ family. I contacted the authors with a couple of questions/observations: They highlighted that systematic reviews used systematic methods which could be … Continue reading All in the Family, a follow-up

Why do we do systematic reviews, part 1 version 2

At the start of the ‘Why do we do systematic reviews?’ series I started with a poll embedded in the first article. It acted as a springboard for the subsequent articles.  Over the course of writing the series I felt that the questions would have benefitted from greater clarity.  So, I want to re-run the survey, with clearer questions, and throw it open to a … Continue reading Why do we do systematic reviews, part 1 version 2