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Year : 2020  |  Volume : 68  |  Issue : 1  |  Page : 204--205

Author‑Based versus Group‑Based Systemic Reviews and Meta‑Analysis

Sunil K Raina 
 Department of Community Medicine, DR. RPGMC, Tanda, Kangra, Himachal Pradesh, India

Correspondence Address:
Dr. Sunil K Raina
Department of Community Medicine, DR. RPGMC, Tanda, Kangra - 176 001, Himachal Pradesh

How to cite this article:
Raina SK. Author‑Based versus Group‑Based Systemic Reviews and Meta‑Analysis.Neurol India 2020;68:204-205

How to cite this URL:
Raina SK. Author‑Based versus Group‑Based Systemic Reviews and Meta‑Analysis. Neurol India [serial online] 2020 [cited 2021 Jan 17 ];68:204-205
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Full Text

I went through with interest the article the article titled “Role of Aspirin in Tuberculous Meningitis: A Systematic Review and Meta-analysis” published in Neurology India (Neurol India 2019; 67:993-1002),[1] primarily because of my interest in Systematic Reviews and Meta-analysis. I must congratulate the authors for their effort despite the known difficulties faced by individual authors in conducting a meta-analysis when comparing it with group or consortia conducted reviews and meta-analysis. This communication without going into merits or otherwise of this meta-analysis is intended at raising some important issues associated with author-based reviews.

A meta-analysis infers from information gathered from multiple studies. This information can be synthesized either prospectively or retrospectively. In an ideal scenario, meta-analyses should be primary research efforts in which different investigators collaborate preemptively in a group or consortia with embedded replication across teams and joint analyses. This model has been successfully tested in large consortia conduct prospective meta-analyses of genome data.[2] But as in this case, systematic reviews and meta-analyses remain retrospective exercises.

Group-based reviews, like the Cochrane review, have a definite advantage over author-based systematic reviews as the group infuses independence into systematic review. In the present study, despite the Cochrane Collaboration's tool, the study selection, data extraction, and risk of bias assessment were conducted by the authors themselves who may have a conflict of interest. Assigning this job to nonauthors would have ensured independence.

Once again, as in this case, there is a steep narrowing down of studies in author-based studies. In the study under reference, from a total of 72 studies identified by searching the mentioned sources, 56 remained after eliminating the duplicate titles, finally narrowing down to only four articles.[1] The drawing of conclusions in this study from a small number of studies may not do justice to the conclusions drawn. The construction of forest plots on this small number could have been avoided. Authors in the past have emphasized the use of forest plots only when there are sufficient studies to make them of value.[3]

Despite the unfavorable evidence presented above, author-based systematic reviews and meta-analyses can still have major value provided more is done to improve the quality of the review by involving different stakeholders: methodologists, academics, scholars, and volunteers trained to handle systematic reviews tools.

One remedy suggested to improve the quality of systematic reviews and meta-analysis has been the preregistration of full protocols to improve transparency and perhaps also to help increase the quality of these studies. But the fact remains that at present only a small fraction of systematic reviews (perhaps 10%–20%) are recorded in registers such as PROSPERO before they start.[4],[5] As preregistration is not the complete answer to improve the quality, what we probably require is more concerted action among key stakeholders. Journals have to play a major role in involving stakeholders by initiating systematic reviews in key researchable areas through invitation to groups interested in publishing systematic reviews and meta-analysis.

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Conflicts of interest

There are no conflicts of interest.


1Rizvi I, Garg RK, Malhotra HS, Kumar N, Uniyal R. Role of aspirin in tuberculous meningitis: A systematic review and meta-analysis. Neurol India 2019;67:993-1002.
2Panagiotou OA, Willer CJ, Hirschhorn JN, Ioannidis JP. The power of meta-analysis in genome-wide association studies. Annu Rev Genomics Hum Genet 2013;14:441-65.
3Raina SK. Interpreting forest plots and funnel plots in meta-analysis. Neurol India 2016;64:840.
4Booth A, Stewart L. Trusting researchers to use open trial registers such as PROSPERO responsibly. BMJ 2013;347:f5870.
5Booth A, Clarke M, Dooley G, Ghersi D, Moher D, Petticrew M, et al. The nuts and bolts of PROSPERO: An international prospective register of systematic reviews. Syst Rev 2012;1:2.