Featured Research

from universities, journals, and other organizations

Approach used to conduct meta-analyses may affect outcomes

Date:
August 12, 2014
Source:
JAMA - Journal of the American Medical Association
Summary:
Depending on the analysis strategy used, estimating treatment outcomes in meta-­analyses may differ and may result in major alterations in the conclusions derived from the analysis, according to a study. Meta-analyses of randomized clinical trials (RCTs) are generally considered to provide among the best evidence of efficacy of medical interventions. They should be conducted as part of a systematic review, a scientifically rigorous approach that identifies, selects, and appraises all relevant studies.

Depending on the analysis strategy used, estimating treatment outcomes in meta­analyses may differ and may result in major alterations in the conclusions derived from the analysis, according to a study in the August 13 issue of JAMA.

Related Articles


Meta-analyses of randomized clinical trials (RCTs) are generally considered to provide among the best evidence of efficacy of medical interventions. They should be conducted as part of a systematic review, a scientifically rigorous approach that identifies, selects, and appraises all relevant studies. Which trials to combine in a meta­analysis remains a persistent dilemma. Meta-analysis of all trials may produce a precise but biased estimate, according to background information in the article.

Agnes Dechartres, M.D., Ph.D., of the Centre de Recherche Epidemiologie et Statistique, INSERM U1153, Paris, and colleagues compared treatment outcomes estimated by meta-analysis of all trials and several alternative strategies for analysis: single most precise trial (i.e., trial with the narrowest confidence interval), meta-analysis restricted to the 25 percent largest trials, limit meta-analysis (a meta-analysis model adjusted for small-study effect), and meta-analysis restricted to trials at low overall risk of bias. The researchers included 163 meta-analyses published between 2008 and 2010 in high-impact-factor journals and between 2011 and 2013 in the Cochrane Database of Systematic Reviews: 92 (705 RCTs) with subjective outcomes and 71 (535 RCTs) with objective outcomes.

The researchers found that treatment outcome estimates differed depending on the analytic strategy used, with treatment outcomes frequently being larger with meta-analysis of all trials than with the single most precise trial, meta-analysis of the largest trials, and limit meta­analysis. The difference in treatment outcomes between these strategies was substantial in 47 of 92 (51 percent) meta-analyses of subjective outcomes and in 28 of 71 (39 percent) meta-analyses of objective outcomes. The authors did not find any difference in treatment outcomes by overall risk of bias.

"In this study, we compared meta-analysis of all trials with several 'best­evidence' alternative strategies and found that estimated treatment outcomes differed depending on the strategy used. We cannot say which strategy is the best because … we cannot know with 100 percent certainty the truth in any research question. Nevertheless, our results raise important questions about meta-analyses and outline the need to re­think certain principles," the researchers write.

"We recommend that authors of meta-analyses systematically assess the robustness of their results by performing sensitivity analyses. We suggest the comparison of the meta-analysis result to the result for the single most precise trial or meta­analysis of the largest trials and careful interpretation of the meta-analysis result if they disagree."

Editorial: Meta-analysis as Evidence -- Building a Better Pyramid

Jesse A. Berlin, Sc.D., of Johnson & Johnson, Titusville, N.J., and Robert M. Golub, M.D., Deputy Editor, JAMA, write in an accompanying editorial that "findings such as those in the study by Dechartres et al reinforce concerns that journals and readers have about meta­analysis as a study design. Those findings deserve consideration not only in the planning of the studies but in the journal peer review and evaluation. They also reinforce the need for circumspection in study interpretation."

"Meta-analysis has the potential to be the best source of evidence to inform decision making. The underlying methods have become much more sophisticated in the last few decades, but achieving this potential will require continued advances in the underlying science, parallel to the advances that have occurred with other biomedical research design and statistics. Until that occurs, an informed reader must approach these studies, as with all other literature, as imperfect information that requires critical appraisal and assessment of applicability of the findings to individual patients. This is not easy, and it requires skill and intelligence. Whatever clinical evidence looks like, and wherever it is placed on a pyramid, there are no shortcuts to truth."


Story Source:

The above story is based on materials provided by JAMA - Journal of the American Medical Association. Note: Materials may be edited for content and length.


Journal References:

  1. Agnes Dechartres, Douglas G. Altman, Ludovic Trinquart, Isabelle Boutron, Philippe Ravaud. Association Between Analytic Strategy and Estimates of Treatment Outcomes in Meta-analyses. JAMA, 2014; 312 (6): 623 DOI: 10.1001/jama.2014.8166
  2. Jesse A. Berlin, Robert M. Golub. Meta-analysis as Evidence. JAMA, 2014; 312 (6): 603 DOI: 10.1001/jama.2014.8167

Cite This Page:

JAMA - Journal of the American Medical Association. "Approach used to conduct meta-analyses may affect outcomes." ScienceDaily. ScienceDaily, 12 August 2014. <www.sciencedaily.com/releases/2014/08/140812163316.htm>.
JAMA - Journal of the American Medical Association. (2014, August 12). Approach used to conduct meta-analyses may affect outcomes. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2014/08/140812163316.htm
JAMA - Journal of the American Medical Association. "Approach used to conduct meta-analyses may affect outcomes." ScienceDaily. www.sciencedaily.com/releases/2014/08/140812163316.htm (accessed October 30, 2014).

Share This



More Science & Society News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama: The US Will Not 'run and Hide' From Ebola

Obama: The US Will Not 'run and Hide' From Ebola

AP (Oct. 29, 2014) — Surrounded by health care workers in the White House East Room, President Barack Obama said the U.S. will likely see additional Ebola cases in the weeks ahead. But he said the nation can't seal itself off in the fight against the disease. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Lowe's Testing Robot Sales Assistants in California Store

Lowe's Testing Robot Sales Assistants in California Store

Buzz60 (Oct. 29, 2014) — Lowe’s is testing out what it’s describing as a robotic shopping assistant in one of its Orchard Supply Hardware Stores in California. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
States And White House Disagree On Ebola Quarantines

States And White House Disagree On Ebola Quarantines

Newsy (Oct. 29, 2014) — Officials in New Jersey and Maine have quarantined Doctors Without Borders nurse Kaci Hickox, a move the White House doesn't seem to support. Video provided by Newsy
Powered by NewsLook.com
New Wave of Online Delivery Gains Momentum

New Wave of Online Delivery Gains Momentum

AFP (Oct. 29, 2014) — With start-ups like Postmates offering quick delivery of meals, groceries and other items through a smartphone app, the online world is delivering again. Duration: 01:39 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Science & Society

Business & Industry

Education & Learning

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins