Epidemiology of systematic reviews in imaging journals




Poster session 2


Monday 17 September 2018 - 12:30 to 14:00

All authors in correct order:

Alabousi M1, Alabousi A1, McGrath TA2, Cobey KD3, Budhram B2, Frank RA2, Nguyen F2, Salameh J4, Sharifabadi AD2, McInnes MD5
1 Department of Radiology, McMaster University, Canada
2 Faculty of Medicine, University of Ottawa, Canada
3 Centre for Journalology, Clinical Epidemiology Program, The Ottawa Hospital Research Institute, Canada
4 School of Epidemiology and Public Health, University of Ottawa, Canada
5 Department of Radiology, University of Ottawa, Canada
Presenting author and contact person

Presenting author:

Mostafa Alabousi

Contact person:

Abstract text
Publication rates for systematic reviews (SRs) have grown, while the rate of publication of original research may not be keeping pace. It is unclear whether these trends are sustainable and are reflected in imaging research.

To evaluate the epidemiological characteristics, publication rates and sustainability of SRs in imaging journals.

A MEDLINE search identified SRs published in 72 imaging journals from 1 January 2000 to 31 December 2016. We screened the articles retrieved against the inclusion criteria. We extracted demographic and methodological characteristics from eligible studies. We evaluated temporal trends using linear regression and Pearson correlation coefficients (r). We calculated the 'sustainability coefficient' based on a ratio of all published non-SRs to the primary studies included in all SRs; a value > 1 suggests sufficient primary study publication to sustain SR output.

We included 921 SRs, which reported on 27,435 primary studies, 85,276,484 patients and which were cited 26,961 times. From 2000 to 2016, the SR publication rate increased 23-fold (r = 0.92, P < 0.001) and the proportion of SRs to non-SRs increased 13-fold (r = 0.94, P < 0.001). SR publication rates for the top five countries are shown by year (Figures 1) and journal impact factor (Figure 2). Table 1 illustrates temporal trends for types of SR, meta-analyses, author teams and funding. Diagnostic test accuracy SRs were most frequent (46.5%) of which one in five compared more than one diagnostic test. Most SRs did not report funding status (54.2%). The reporting of funding and the proportion of non-funded SRs increased over time. The median author team size was five; this increased over time. An imaging specialist co-author was included in 67.3% of studies; this decreased over time. Most SRs included a meta-analysis (69.6%) and a minority included an individual patient data meta-analysis (11.1%). Journal impact factor positively correlated with SR publication rates (r = 0.54, P < 0.001). There were 168,074 non-SRs published with a sustainability coefficient of 6.13.

The SR publication rate is increasing rapidly compared with the rate of non-SRs. However, the present sustainability coefficient appears to be supportable; monitoring of the sustainability coefficient may be warranted to ensure SRs remain sustainable in imaging journals. Epidemiological SR features changed over time.


Relevance to patients and consumers: 

Patient and consumer partners assisted in the authors in producing this statement. This research helps identify regions performing more imaging systematic reviews (Europe and North America), as well as regions where such research is less common and which could be targets for awareness and knowledge translation activities. The publication rate of systematic reviews in imaging journals is identified, and compared to trends for all researching imaging journals to determine whether is the growth in systematic reviews is sustainable. At this time, the publication rate of systematic reviews appears to be sustainable, but is growing rapidly.