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Entries in Systematic Reviews (22)

Sunday
Jul142013

Are systematic reviews up-to-date at the time of publication?

PMCID: PMC3674908

From the discussion:

Of the 90% of our 300 systematic reviews that provided a date of search, the median time from last search to publication was 8.0 months. This is an improvement over the results reported in 2008 where the median time was around 14 months [10]. However, the distribution in our study was skewed, with around 10% of reviews having a last search date to publication time of more than 18 months. Since reviews can date rapidly [8], this delay is important to users of reviewers.

For a reader searching for an up-to-date review, the relevant date is that of the last search not the date of publication, but this was provided in only 47% of abstracts. Hence readers would need to check, and possibly purchase, the full text to determine recency. Similarly, readers may wish to know the list of databases searched to assess completeness of the review, but this was missing from 40% of abstracts.

The time from search to publication can be usefully compared with the half-life of a review’s conclusions. One analysis of 100 systematic reviews found the half-life was 5.5 years until there was a change in the clinical conclusions of a review [8]. That analysis also found that 7% of reviews were out of date on the day of publication. That is, new research that changed the clinical conclusions was published between the date of search and the date of publication. This is consistent with our finding of a median time from last search to publication delay of 8.0 months.

We found no previous studies on the reporting of dates in abstracts, but several studies have examined the search dates and other items in the full text of reviews. An analysis of 65 Cochrane reviews found that 91% reported the years searched, but only 11% gave the date of last search [13]. Similarly, a study of 297 systematic reviews found that 70% reported the dates covered by the search, and 77% gave the end date of search, but these were better reported in Cochrane reviews (83% and 91%, respectively) than in non-Cochrane reviews (60% and 67%, respectively) [14].

Beller EM, Chen JK, Wang UL, Glasziou PP. Are systematic reviews up-to-date at the time of publication? Syst Rev. 2013 May 28;2:36. doi: 10.1186/2046-4053-2-36. PMCID: PMC3674908.

Wednesday
Feb272013

Out-of-Date Systematic Reviews

This paper compares 5 statistical methods for identifying out of date SRs: 

While I'm not going to be running statistical tests to identify out-of-date reviews, knowing that such tests exist might come in handy at some point when chatting w/ researchers. 

[via Evidence-Based Health]

Pattanittum P, Laopaiboon M, Moher D, Lumbiganon P, Ngamjarus C. (2012). A comparison of statistical methods for identifying out-of-date systematic reviews.  PLoS One, 7(11). PMID 23185281 PMC3502410

Monday
Feb042013

Outcome Reporting Bias

And its effect on systematic review outcomes.  Study.

The reliability of systematic reviews, in particular meta-analyses they contain, can be improved if more attention is paid to missing outcome data. The availability of [core outcome sets] for specific health conditions might help with this and the concept has support from the majority of Co-ordinating Editors in [Cochrane review groups].

I seem to be coming across a number of bias in SR papers recently, as well as - not coincidentally, I'm sure - discussions re: the need for better, more consistent reporting. 

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Kirkham JJ, Gargon E, Clarke M, Williamson PR. Can a core outcome set improve the quality of systematic reviews? -- a survey of the Co-ordinating Editors of Cochrane review group. Trials. 2013 Jan 22;14(1):21. 

Wednesday
Jan162013

PROSPERO At One Year

Some PROSPERO data (of SRs registered in their system):

PROSPERO at one year: an evaluation of its utility. (PDF)
Systematic Reviews 2013, 2(4)
Booth A, Clarke M, Dooley G, Ghersi D, Moher D, Petticrew M,
Stewart L. 

Friday
Jan112013

Google Scholar & Systematic Reviews

Is Google Scholar Enough for SR Searches? No

I agree.  

Is the coverage of google scholar enough to be used alone for systematic reviews 
BMC Med Inform Decis Mak. 2013 Jan 9;13(1)
Jean-François G, Laetitia R, Stefan D. 
PMID: 23302542