Evidence map›Paper›PMID 26537988›Full record

ArticleSystematic reviews2015

Network meta-analysis incorporating randomized controlled trials and non-randomized comparative cohort studies for assessing the safety and effectiveness of medical treatments: challenges and opportunities.

Chris Cameron, Bruce Fireman, Brian Hutton, Tammy Clifford, Doug Coyle, George Wells, Colin R Dormuth, Robert Platt, Sengwee Toh

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Systematic reviews, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 62 papers, 27 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
62citing papers in PubMed, 27 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

62 citing papers in PubMed, 27 syntheses or guidelines pooled it.

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  4. Hydrosalpinx treatment before in-vitro fertilization: systematic review and network meta-analysis.Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology · 2025
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2 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Chris CameronSchool of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, 451 Smyth Road, Suite RGN 3105, Ottawa, ON, K1H 8 M5, Canada. ccame056@uottawa.ca.
Bruce FiremanDivision of Research, Kaiser Permanente Northern California, 2000 Broadway, Oakland, CA, 94612, USA. bruce.fireman@kp.org.
Brian HuttonSchool of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, 451 Smyth Road, Suite RGN 3105, Ottawa, ON, K1H 8 M5, Canada. bhutton@ohri.ca.
Tammy CliffordSchool of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, 451 Smyth Road, Suite RGN 3105, Ottawa, ON, K1H 8 M5, Canada. Tammyc@cadth.ca.
Doug CoyleSchool of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, 451 Smyth Road, Suite RGN 3105, Ottawa, ON, K1H 8 M5, Canada. dcoyle@uottawa.ca.
George WellsSchool of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, 451 Smyth Road, Suite RGN 3105, Ottawa, ON, K1H 8 M5, Canada. gawells@ottawaheart.ca.
Colin R DormuthDepartment of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada. colin.dormuth@ti.ubc.ca.
Robert PlattDepartment of Epidemiology and Biostatistics, McGill University, 4060 Ste Catherine W #300, Montréal, Québec, H3Z 2Z3, Canada. robert.platt@mcgill.ca.
Sengwee TohDepartment of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, 133 Brookline Avenue, 6th Floor, Boston, MA, 02215, USA. darren_toh@harvardpilgrim.org.

Funding

Canadian Institutes of Health Research
6 · The paper itself

Abstract

Network meta-analysis is increasingly used to allow comparison of multiple treatment alternatives simultaneously, some of which may not have been compared directly in primary research studies. The majority of network meta-analyses published to date have incorporated data from randomized controlled trials (RCTs) only; however, inclusion of non-randomized studies may sometimes be considered. Non-randomized studies can complement RCTs or address some of their limitations, such as short follow-up time, small sample size, highly selected population, high cost, and ethical restrictions. In this paper, we discuss the challenges and opportunities of incorporating both RCTs and non-randomized comparative cohort studies into network meta-analysis for assessing the safety and effectiveness of medical treatments. Non-randomized studies with inadequate control of biases such as confounding may threaten the validity of the entire network meta-analysis. Therefore, identification and inclusion of non-randomized studies must balance their strengths with their limitations. Inclusion of both RCTs and non-randomized studies in network meta-analysis will likely increase in the future due to the growing need to assess multiple treatments simultaneously, the availability of higher quality non-randomized data and more valid methods, and the increased use of progressive licensing and product listing agreements requiring collection of data over the life cycle of medical products. Inappropriate inclusion of non-randomized studies could perpetuate the biases that are unknown, unmeasured, or uncontrolled. However, thoughtful integration of randomized and non-randomized studies may offer opportunities to provide more timely, comprehensive, and generalizable evidence about the comparative safety and effectiveness of medical treatments.

Indexed as

Drug TherapyMeta-Analysis as TopicResearch DesignCohort StudiesComparative Effectiveness ResearchConfounding Factors, EpidemiologicDrug-Related Side Effects and Adverse ReactionsHumansObservational Studies as TopicPharmacoepidemiologyRandomized Controlled Trials as TopicSelection Bias

Identifiers

PMID26537988
PMCPMC4634799

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.