Theorising about evidence synthesis – is it about the cost, language or other?

As far as I can tell we undertake evidence synthesis to better understand the effectiveness of an intervention.  The rationale is that the greater the accumulation of evidence the greater the understanding of how good an intervention is.  This is typically characterised by a reduction in the size of the confidence intervals in meta-analyses.  Put it another way, we attempt to be as certain as … Continue reading Theorising about evidence synthesis – is it about the cost, language or other?

Update from author: Trading certainty for speed

In the recent post relating to trading certainty for speed I highlighted that the authors stated: “Participants of our survey, on average, viewed 10% as the maximum tolerable risk of getting an incorrect answer from a rapid review” My issue with this is that there was no definition of what ‘incorrect’ was.  So, I emailed one of the authors: “A fascinating paper, thank you.  One … Continue reading Update from author: Trading certainty for speed

Can it really be true that 50% of research is unpublished?

Paul Glasziou and Iain Chalmers recently published the above article on the BMJ Blog.  As you’d expect with these authors it’s a great read.  I’d like to highlight one section – that’s particularly relevant to the issue of rapid reviews (Note my emphasis): Whether the precise non-publication rate is 30%, 40%, or 50%, it is still a serious waste of the roughly $180 billion annually … Continue reading Can it really be true that 50% of research is unpublished?

Registering rapid reviews

One category on the Trip Database is ‘ongoing systematic reviews’. This content is taken from the PROSPERO database of ongoing systematic reviews.  If you’re not familiar with PROSPERO this is how the site describes itself: “PROSPERO is an international database of prospectively registered systematic reviews in health and social care, welfare, public health, education, crime, justice, and international development, where there is a health related … Continue reading Registering rapid reviews

Unpublished studies in stem cells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  Avoiding unpublished trials can massively affect a systematic review [1, 2].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