On 2016 Sep 16, Hilda Bastian commented:

I have posted updated data on key charts here. The data are updated to 2013 for the charts with systematic reviews and 2014 for trials.

If you are interested in this topic, the Page MJ, 2016 paper is a must read. We relied in large part on filters to chart trends: Page and colleagues rigorously studied a month's worth of systematic reviews from 2014.

Disclosure: I work on projects related to systematic reviews at the NCBI (National Center for Biotechnology Information, U.S. National Library of Medicine), including some aspects that relate to the inclusion of systematic reviews in PubMed.

On 2013 Nov 12, Paulo Rossetti commented:

The way to communicate science for general clinics is a complicated issue. Meta-analysis could be a two-page article only with what is extremely necessary for clinics. Maybe, some people can design a self-explained forest plot similar to what we have now for some themes with smartphone technologies.

On 2013 Dec 06, Lorraine Johnson commented:

It is not possible to keep up. Stepping back down the food chain a moment to RCTs. Consider the use of RCTs to solve combination regimen questions. Answer: cannot be done in our lifetime. We need better (and faster) tools. The summation of these efforts will necessarily incorporate the weaknesses of the underlying data to provide answers. See Saver re combination regimen RCTs and duration to answer.Saver JL, 2001 "Strategies for testing combination regimens include: head to head trials of all combinations, which lead to unwieldy trial numbers; very large multi-arm trials, which impractically delay interval information on regimen utility; and hierarchical, serial clinical trials. Systematic literature review revealed seven classes of agents already approved or in late phase III testing for preventing the development or slowing the progression of Alzheimer disease and five for ischemic stroke prevention. Possible combination regimens number 128 (2(7)) for Alzheimer disease and 32 (2(5)) for ischemic stroke. Hierarchical, serial clinical trials would permit identification of the optimum combination of these agent classes for Alzheimer disease through 127 trials, enrolling 63,500 patients, requiring 286 years; for ischemic stroke through 31 trials, enrolling 186,000 patients, requiring 155 years."

On 2013 Nov 13, Hilda Bastian commented:

Yes, that's an important point to keep in mind: this is just indicative of trends, not a way to find reviews that are rigorously systematic. The methods we used based on the Montori filter are detailed in the supporting information for the article here.

Filters are not the only way to identify systematic reviews via PubMed services. There is information on ways of finding curated systematic reviews at PubMed Health as well as via PubMed here. (Disclosure: I work on the PubMed Health project.)

On 2013 Nov 13, Amy Donahue commented:

I appreciate the appendix/supplemental data explaining how you counted/found systematic reviews. I do wonder about the quality of the SRs found using the Montori filter - as my colleagues and I (medical librarians) are asked more often to help with the searches for systematic reviews, we're finding that authors are calling many things "systematic" when they really aren't, and many journals don't hold SRs to the standards put out by the various organizations.

That aside, we are more than happy to help with the movement of prioritizing the creation of systematic reviews and our skills can be utilized in their creation. And 3 cheers for making sure they're accessible to both patients and clinicians!

On 2013 Nov 12, Hilda Bastian commented:

We haven't updated the data on trials yet, but will. Trials are subject to some different influences than systematic reviews, such as the impact in recent years of trial registration on the proportion of conducted trials being reported. Yes, the relationship between the two would be interesting to understand.

On 2013 Nov 11, Jamie Horder commented:

Thanks for this update. I wonder, has the number of primary trials published per day risen to the same extent?

My (wholly qualitative) impression is that the ratio of primary:metaanalysis publications has been falling in recent years; it would be interesting to find some evidence on that point.

On 2013 Nov 01, Hilda Bastian commented:

Our estimation of "11 systematic reviews a day" is out of date. There has been a striking increase in systematic reviews since that original analysis (ending with data from 2007). In August 2013 Paul Glasziou and I updated the data in Figure 3 estimating the number of systematic reviews, including data up to 2012.

The update showed that by 2012, there were around 26 systematic reviews a day. The updated figure is available here. Addressing the challenges we identified in keeping up with the evidence have thus become more critical.

(We are grateful to Claire Allen at the Cochrane Collaboration for providing the data on the number of Cochrane reviews.)

On 2013 Nov 01, Hilda Bastian commented:

Our estimation of "11 systematic reviews a day" is out of date. There has been a striking increase in systematic reviews since that original analysis (ending with data from 2007). In August 2013 Paul Glasziou and I updated the data in Figure 3 estimating the number of systematic reviews, including data up to 2012.

The update showed that by 2012, there were around 26 systematic reviews a day. The updated figure is available here. Addressing the challenges we identified in keeping up with the evidence have thus become more critical.

(We are grateful to Claire Allen at the Cochrane Collaboration for providing the data on the number of Cochrane reviews.)

On 2013 Nov 12, Paulo Rossetti commented:

The way to communicate science for general clinics is a complicated issue. Meta-analysis could be a two-page article only with what is extremely necessary for clinics. Maybe, some people can design a self-explained forest plot similar to what we have now for some themes with smartphone technologies.

On 2016 Sep 16, Hilda Bastian commented:

I have posted updated data on key charts here. The data are updated to 2013 for the charts with systematic reviews and 2014 for trials.

If you are interested in this topic, the Page MJ, 2016 paper is a must read. We relied in large part on filters to chart trends: Page and colleagues rigorously studied a month's worth of systematic reviews from 2014.

Disclosure: I work on projects related to systematic reviews at the NCBI (National Center for Biotechnology Information, U.S. National Library of Medicine), including some aspects that relate to the inclusion of systematic reviews in PubMed.