Editorial
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Meta-Anal. Aug 26, 2015; 3(4): 188-192
Published online Aug 26, 2015. doi: 10.13105/wjma.v3.i4.188
Application of meta-analysis to specific research fields: Lessons learned
Lynne V McFarland
Lynne V McFarland, Department of Medicinal Chemistry, University of Washington, Seattle, WA 98108-1597, United States
Lynne V McFarland, VA Puget Sound Healthcare System, Seattle, WA 98108-1597, United States
Author contributions: McFarland LV contributed solely to this work.
Conflict-of-interest statement: The author has no support from any organization for the submitted work; no financial relationships with any organizations that might have an interest in the submitted work, not other relationships or activities that could appear to have influenced the submitted work.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Lynne V McFarland, PhD, VA Puget Sound Healthcare System, 1660 S. Columbian Way, Seattle, WA 98108-1597, United States. lynne.mcfarland@va.gov
Telephone: +1-206-2771780 Fax: +1-206-7642935
Received: May 5, 2015
Peer-review started: May 7, 2015
First decision: June 3, 2015
Revised: June 15, 2015
Accepted: July 7, 2015
Article in press: July 9, 2015
Published online: August 26, 2015
Processing time: 132 Days and 4.2 Hours
Abstract

Scientific research is challenged to translate findings from multiple, often conflicting, clinical trials into a simple answer of whether a treatment works or not. The public and healthcare providers alike frequently voice their frustrations when the media reports a treatment working on one day, but seemingly the next day reports a study refuting the previous one. Meta-analyses are being used more commonly by researchers to convey an understandable summary of scientific studies to the general public and healthcare providers. As time goes by, we have learned how to improve meta-analytic techniques to reflect more valid results and when it is appropriate to pool or not to pool results from different studies. Retrospective reviews often don’t acknowledge this learning curve and may fail to recommend the most current valid guidelines. This editorial presents an example of how the current use of meta-analysis has shifted in one field (the therapeutic effects of probiotics) and recommendations on how to correctly interpret the results of such an analysis.

Keywords: Meta-analysis; Study designs; Probiotics; Sensitivity analysis; Meta-regression

Core tip: As meta-analyses are used more frequently and their findings reach a wider scope of people, it is the responsibility of researchers to use current guidelines and appropriately apply their findings to form valid conclusions. As researchers gain experience with this technique, we need to recognize that our methods may change over time. Meta-analysis remains a valuable tool for examining controversies arising from conflicting studies.